Which situation might lead to an abnormal account balance?

An abnormal account balance is typically identified when the balance in an account does not align with the expected nature of that account based on standard accounting principles. An overpayment of an account receivable by a customer can lead to an abnormal balance because it results in a negative balance in the accounts receivable account.

In a normal scenario, accounts receivable should have a positive balance that reflects amounts owed to the business by customers. However, if a customer overpays—perhaps sending more than the invoice amount—this can create a scenario where the account balance is artificially inflated or even negative if the payment exceeds the outstanding amount. This inconsistency signifies a departure from the typical activity associated with accounts receivable, resulting in an abnormal account balance.

In contrast, the other options, while potentially problematic in their own right, are less likely to culminate in an abnormal balance due to the nature and standard expectations of their account classifications. The underpayment of an account payable or the underaccrual of interest expense would affect the financial statements but would not typically create an abnormal balance like an overpayment in accounts receivable does.