Answer (B) is correct.
The allowance method attempts both to match the expense with the
related revenue and to determine the NRV of the accounts receivable.
This method is acceptable under GAAP. The direct write-off method
debits expense and credits accounts receivable at the time uncollectibility
is established. This method does not match revenue and expense or state
receivables at NRV. It is not acceptable under GAAP.