Answer:
C. Debit Allowance for Doubtful Accounts and credit Accounts Receivable
Explanation:
To write-off an account under the allowance method, the company will decrease both, the allowance and the receivables. This will leave the net receivable at the same value before the write-off. It will have no impact on the net income as the account used are an asset account and contra-asset account.
The company will never write-off against bad debt expense under the allowance method. That is done in the direct method.