The correct option is A debit side of sales returns A/c
When the goods sold are return back to the vendor it is recorded in sales return book. Buyer may return the goods due to poor quality of goods or inaccurate quantity or other reasons etc. It is also called as return inwards. All returns are primarily recorded in sales return book unless the returns are not the frequent, in which case they are recorded in the Journal. After updating transactions in sales return book, the total of the items is transferred to ledger in an account called the "Sales Returns A/c".