Abalone Corp. uses a periodic inventory system. In the month of July, 2021, it made the following purchases: Beginning inventory 20 units @ $19 $ 380 Jul 1 7 Purchases 22 Purchases 70 units @ $20 1,400 10 units @ $22 220 $2,000 A physical count of merchandise inventory on July 31 shows that 25 units are on hand. Under the average cost method, cost of goods sold for July was $1,500. $520. $500. $1,600.