You must complete parts 1,2,3,4,6,7,8 and 9 before attempting to complete part 10. Part 5 is the optional worksheet. Prepare a post-closing trial balance. If an amount box does not require an entry, leave it blank. Customers Refunds Payable Common Stock Retained Earnings You must complete parts 1,2,3,4,6,7,8 and 9 before attempting to complete part 10. Part 5 is the optional worksheet. Prepare a post-closing trial balance. If an amount box does not require an entry, leave it blank. Customers Refunds Payable Common Stock Retained Earnings