Barrett Realtors always collects rent in advance from its customers. The 2013 income statement for Barrett reports rent revenue of $21,000. The related balance sheet accounts for the beginning and end of the year were: Jan. 1, 2013 Dec. 31, 2013 Unearned Rent $3,500 $6,500 Based on this information, the amount of cash collected during 2013 from Barrett's customers was: Select one: A. $ 7,750 B. $24,000 C. $28,250 D. $26,500