Answer:
b.There is no effect on the accounting equation as one asset account increases while another asset account decreases.
Explanation:
On billing the customer, sales account would have been credited and accounts receivables debited.
On payment by the customer, accounts receivables would be credited and cash account debited.
Hence there will be no increase/decrease in asset as cash and receivables would nil off.
As such, the right option is b.There is no effect on the accounting equation as one asset account increases while another asset account decreases.