On March 12, Klein Company 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 and the gross method of accounting for sales. 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 amount that Klein receives from Babson on March 20 is:

A) $7,800.

B) $7,644.

C) $7,044.

D) $7,056.

E) $7,200.