I only need help with the 3rd and 4th requirement. i have already done the 1st and 2nd

During 2021, WMC Corporation discovered that its ending inventories reported on its financial statements were misstated by the following amounts: 2019 understated by 2020 overstated by $156,000 222,000 WMC uses the periodic inventory system and the FIFO cost method. Required: 1-a. Determine the effect of 2019 errors on retained earnings at January 1, 2021, before any adjustments. (Ignore income taxes.) 1-b. Determine the effect of 2020 errors on retained earnings at January 1, 2021, before any adjustments. (Ignore income taxes.) 2. Prepare a journal entry to correct the error in 2021. 3. Will WMC account for the error (a) retrospectively or (b) prospectively? Answer is not complete. Complete this question by entering your answers in the tabs below. Req 1A Req 1B Reg 2 Req3 Prepare a journal entry to correct the error in 2021. (If no entry is required for a transaction/event, select "No journal entry required" in the first account field.) No Event General Journal Debit Credit