Control Account

The sales control account at 1 May had balances of $32,750 debit and $1,275 credit. During May, sales of $125,000 were made on credit. Receipts from debitors amounted to $122,500 and cash discounts of $550 were allowed. Refunds of $1,300 were made to customers.

The closing balances at 31 May could be:
A. $35,125 debit and $3,000 credit
B. $35,675 debit and $2,500 credit
C. $36,725 debit and $2,000 credit
D. $36,725 debit and $1,000 credit

The answer is A. How to calucate the answer?