At December 31, 2010, Gill Co reported accounts receivable of $216,000 and an allowance for uncollectible accounts of $8,400. During 2011, accounts receivable increased by $22,000, and $7,800 of bad debts were written off. An analysis of Gill Co.'s December 31, 2011, accounts receivable suggests that the allowance for uncollectible accounts should be 3% of accounts receivable. Bad debt expense for 2011 would be

A. $600.

B. $7,800.

C. $7,140.

D. $6,540.