Calculator Addison, Inc. uses a perpetual inventory system. Below is information about one inventory item for the month of September Sep. 1 Inventory 20 units at $20 4 Sold 10 units 10 Purchased 30 units at $25 17 Sold 20 units 30 Purchased 10 units at $30 If Addison uses FIFO, the September 17 entry for cost of goods sold would be: 450 a. Cost of Goods Sold Inventory b. Inventory Cost of Goods Sold c. Sales Cost of Goods Sold d. Cost of Goods Sold Sales 450 450 450