On March 12, Klein Company, Inc. sold merchandise in the amount of $7,800 to Babson Company, with credit terms of 2/10, n/30. The cost of the items sold is $4,500. Klein uses the perpetual inventory system. On March 15, Babson returns some of the merchandise. The selling price of the merchandise is $600 and the cost of the merchandise returned is $350. Babson pays the invoice on March 20, and takes the appropriate discount.
The journal entry that Klein makes on March 20 is:

a) Sales returns and allowances 600
Accounts receivable 600
b) Merchandise inventory 350
Cost of goods sold 350
c) Sales returns and allowances 600
Accounts receivable 600
d) Accounts receivable 600
Sales returns and allowances 600
e) Accounts receivable 600
Sales returns and allowances 600
f) Cost of goods sold 350
Merchandise inventory 350
g) Sales returns and allowances 350
Accounts receivable 350