May I ask for an explanation to the question. Thank you!

[S1] The direct write-off method of bad debts requires a journal entry when the receivables become doubtful of collection. [S2] An aging of accounts receivable makes use of the income statement approach of estimating bad debts expense.

a. Only S1 is true.

b. Only S2 is true.

c. Both S1 and S2 are true.

d. Both S1 and S2 are false