Why is the cost of goods sold account used in the entries instead of the inventory account in the suggested solution? Can someone explain how using the cost of goods sold account works in each entry.

Prepare the pro-forma audit adjusting entries for the following errors discovered when examining the financial statements for the year 2021. The company uses the function of expense method in presenting the expenses. The enterprise has already set up its Cost of Goods Sold account. 1. Ending inventory in 2020 was understated because of non-inclusion of goods in the hands of consignees. 2. Ending inventory in 2021 was overstated due to double-counting of some items. 3. Purchase of goods made late in 2020 was recorded in 2021 , but goods were counted in 2020 ending inventory. 4. Goods purchased at the end of 2021 were recorded when the goods were received in 2022. Goods were also omitted from ending inventory of 2021. 5. Merchandise bought on account and received in December 2020 was omitted from the inventory count made as of December 31,2020 . The purchase was properly recorded in 2020 . 6. Sale of merchandise made in 2020 was recorded only in 2021