Answer:
A. No net effect to the accounting equation
Explanation:
The reason is that on January 1 Knomark recognized an "Accounts Receivable" which is an asset and on January 11 it is just converted into another asset which is "Cash"
The journal entry would look like this on January 11:
(DR) Cash $500
(CR) Accounts Receivable $500
The Accounts receivable is credited thus decreasing the Assets
BUT the cash is debited at the same time which increases the Assets
In effect, there is NO net effect to the Assets and to the accounting equation as a whole.