Option (D) is the correct answer. When rent for a month is still to be paid, it is considered an outstanding expense. Based on the principles illustrated in the provided context (specifically the treatment of 'Outstanding wages' as a Current Liability), outstanding expenses represent a liability for the business. Therefore, the Outstanding Rent Account must be credited. Simultaneously, the Rent Account is a nominal account (expense) that must be debited to reflect the increased expense for the period. Thus, the adjustment entry is to Debit rent account and Credit outstanding rent account.