An unfavorable bank balance means.

Explanation:

A credit balance in the passbook means the holder of the account has an amount in his bank.

In the passbook, the amount withdrawn by the holder is debited and the amount deposited by the holder is credited.

Cashbook is maintained by the firm whereas the passbook is maintained by the bankers.

As per the cash book, the debit balance is the favorable balance for the account holder, and the credit balance is an unfavorable balance.

A debit balance in the passbook means an unfavorable bank balance.

Unfavorable bank balance shows that the holder has taken a loan from the balance so the debit side of the passbook shows more balance than the credit side of the passbook.

Final Answer:

Hence,the correct answer is Option C: Credit balance in passbook.