please , help with this lifo method ? thanks

28. June Corp. sells one product and uses a perpetual inventory system. The beginning inventory consisted of 80 units that cost $20 per unit. During the current month, the company purchased 480 units at $20 each. Sales during the month totaled 360 units for $43 each. What is the cost of goods sold using the LIFO method? [a] $1,600. [b] $7,200. [c] $9,600. [d] $15,480. I n fo accounting perind