Final answer:
The primary purpose of closing entries is to close temporary accounts to set them back to a zero balance for the next accounting period. Correct option is C.
Step-by-step explanation:
The primary purpose of closing entries is C. To close temporary accounts. Closing entries are made at the end of an accounting period to transfer the balances of temporary accounts to permanent accounts. Temporary accounts include revenues, expenses, income summary, and dividends. These accounts are closed to prepare the company's books for the next accounting period. The process of closing ensures that the revenue and expense accounts start with a zero balance in the new accounting period, which is essential for proper revenue and expense tracking.