Novak Corporation, which uses a perpetual inventory system, purchased $2110 of merchandise on July 5 on account. Credit terms were 2/10, n/30. It returned $422 of the merchandise on July 9. Which of the following is one effect when Novak pays its bill on July 21? O Debit to Cash for $1688 Debit to Accounts Payable for $2110 O Credit to Accounts Payable for $1688 O Credit to Cash for $1688