Leonard reminded the hotel clerk that he would need a ______ for his expense account.

The word needed to complete the sentence is "receipt." A receipt is an important document provided by businesses that confirms a transaction and provides details such as the amount spent, the date, and the items or services purchased. In the context of an expense account, a receipt serves as proof of expenditure, which is necessary for reimbursement or record-keeping purposes.

The other options do not represent an actual word or do not convey the correct meaning in this context. "Reseet," "reseat," and "receit" are not related to financial transactions and would not make sense when discussing the documentation required for an expense account. Therefore, "receipt" is the only word that accurately completes the sentence and aligns with the context of expense reporting.