<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><Version>2.4.0.8</Version><ReportLongName>0014 - Disclosure - 9. STOCK-BASED COMPENSATION</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column FlagID="0"><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

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</LabelSeparator><Level>2</Level><ElementName>us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="Context_3ME_30-Apr-2013" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify"&gt;&lt;i&gt;Stock Options&lt;/i&gt;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify"&gt;The Company has a stock-based compensation
plan known as the 2007 Stock Option Plan (the &amp;#147;Plan&amp;#148;). The Plan provides for the granting of incentive and non-qualified
stock options to acquire common shares in the capital of California Gold Corp. The number of shares authorized under the Plan is
16,000,000. As of July 31, 2013, 6,000,000 shares remain available for future grants under the Plan.&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify"&gt;On July 27, 2011, the Company granted
options to purchase 11,000,000 shares of its common stock to its employees and outside consultants. These options have a 10-year
term and were granted with an exercise price of $0.09. One-third of these options, or 3,666,667, vested on the date of the grant,
with the remaining two-thirds vesting on the first and second anniversaries of the date of grant. As of July 31, 2013, a total
of 10,000,000 options had vested, which included an additional 3,333,333 options which vested on July 27, 2012, the first anniversary
of the grant date, and an additional 3,333,333 options which vested on July 27, 2013, the second anniversary of the grant date.
All vested options are exercisable, in full or in part, at any time after vesting, until termination. On May 4, 2012, one of the
Company&amp;#146;s directors resigned and therefore, all of his 666,667 non-vested options terminated on that date and his vested
but unexercised options totaling 333,333 expired and were forfeited on August 4, 2012.&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify"&gt;The Company recorded the stock-based
compensation expense - related party attributable to options of $74,998 and $149,995 during the three and six months ended July
31, 2013, respectively. The Company recorded the stock-based compensation expense - related party attributable to options of $75,284
and $157,782 during the three and six months ended July 31, 2012. As of July 31, 2013, there was no unrecognized compensation cost
related to non-vested stock options. Outstanding options had $0 intrinsic value at July 31, 2013, due to the exercise price being
greater than the value of the Company&amp;#146;s common stock at the reporting date.&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify"&gt;The fair value of options granted in
July 2011 was measured at the date of grant using the Black-Scholes option-pricing model with the following assumptions:&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;table cellspacing="0" cellpadding="0" style="font: 8pt Calibri, Helvetica, Sans-Serif; width: 100%"&gt;
&lt;tr style="vertical-align: bottom; background-color: #CCEEFF"&gt;
    &lt;td style="width: 89%; line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;Market price of the Company&amp;#146;s common stock on grant date&lt;/font&gt;&lt;/td&gt;
    &lt;td style="width: 1%; text-align: right; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="width: 1%; line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;$&lt;/font&gt;&lt;/td&gt;
    &lt;td style="width: 8%; text-align: right; line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;0.09&lt;/font&gt;&lt;/td&gt;
    &lt;td nowrap="nowrap" style="width: 1%; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: white"&gt;
    &lt;td style="line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;Risk free interest rate (1)&lt;/font&gt;&lt;/td&gt;
    &lt;td style="text-align: right; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="text-align: right; line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;3.01 &lt;/font&gt;&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;%&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: #CCEEFF"&gt;
    &lt;td style="line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;Dividend yield&lt;/font&gt;&lt;/td&gt;
    &lt;td style="text-align: right; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="text-align: right; line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;0.00 &lt;/font&gt;&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;%&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: white"&gt;
    &lt;td style="line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;Volatility&lt;/font&gt;&lt;/td&gt;
    &lt;td style="text-align: right; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="text-align: right; line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;259.13 &lt;/font&gt;&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;%&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: #CCEEFF"&gt;
    &lt;td style="line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;Expected life&lt;/font&gt;&lt;/td&gt;
    &lt;td style="text-align: right; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td colspan="2" style="text-align: right; line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;6 years&lt;/font&gt;&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: white"&gt;
    &lt;td style="line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;Expected forfeiture rate&lt;/font&gt;&lt;/td&gt;
    &lt;td style="text-align: right; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="text-align: right; line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;0.00 &lt;/font&gt;&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&lt;font style="font: 8pt Times New Roman, Times, Serif"&gt;%&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;
&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-align: justify"&gt;(1) The risk-free interest rate was determined
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