Answer:
d.The Allowance for Doubtful Accounts has a normal credit balance
Explanation:
Allowance for Doubtful Accounts is a contra asset account and it normally has a credit balance which is adjusted in the debit balance of account receivables. When a write off is recorded this account is debited to record the effect in this account. Under aging method nothing is done with this account, aging method calculates the value and record it. Normally this account has credit balance but sometimes it might have a debit balance when a write off greater than the account balance is recorded.