Can you try to show me how you got the answer step-by-step because I'm having a hard time figuring this out?

Question 5 Deshaun Watson Inc. has the following information related to the purchases and sales of one of their inventory items: Beginning Inventory: 100 units at $10 per unit Purchases: 1/1 30 units @ $9 per unit 4/30- 20 units $ $11 per unit 10/31 50 units at $12 per unit 1/15-90 units sold @ $25 per unit 5/5- 15 units sold @ $25 per unit 11/15-40 units sold @ $20 per unit Sales: Assuming that Watson uses a periodic inventory system and the average cost method, the cost of goods sold (to the nearest dollar) for the period is $1,370 $1,435 $1,515 $1,640