Answer:
C. NA  = NA + NA  NA  − NA = NA  90  OA
Explanation:
* Option for this question have not been provided, the screenshot of same question is attached with this answer.
Amount Recorded = 900
Actual amount = 990
It requires a correcting entry that already been recorded with amount of $90, as follow
             Dr.   Cr.
Cash          90
Account Receivable  90
Effect on Accounting Equation
Asset               =      Equity   +   Liability
Cash +90
Account Receivable -90
Net effect in accounting equation will be zero.
Cash flow from Operating activities will be increased by $90
So
Assets = Liab.  +  EquityRev . −  Expenses = Net Inc.  Cash Flow
NA Â Â Â Â Â NA Â Â Â Â Â NA Â Â Â Â Â Â Â Â Â Â NA Â Â Â Â = Â Â 90 Â Â Â Â Â Â OA