Stone Company's allowance for doubtful accounts had a credit balance of $8,000 at December 31, 19X3. Stone accrues bad debt expense monthly at 4% of credit sales. During 19X4: (1) Stone's credit sales amounted to $1,300,000, and (2) uncollectible accounts totaling $32,000 were written off. The aging of accounts receivable indicated that a $40,000 allowance for doubtful accounts was required at December 31, 19X4. Stone's bad debt expense for 19X4 would A. $64,000 B. $52,000 C. $40,000 D. $32,000