Answer:
C. Monthly
Explanation:
If a business uses a monthly accounting period, it would prepare a post-closing trial balance once a month, at the end of the accounting period. Therefore, the correct answer is option C, monthly.
A post-closing trial balance is a list of all the accounts and their balances after adjusting entries have been made and closing entries have been posted to the general ledger. It is used to verify that the debits and credits are equal and that all temporary accounts have been closed out. The post-closing trial balance is prepared after the closing entries have been made at the end of the accounting period. For a business that uses a monthly accounting period, this would typically be done once a month, at the end of each month.