The inventory records for Grays Company showed the following transactions during the first two weeks of September: Date Activities Beginning Units Acquired at Cost Units Sold at Retail September 1 15 units @ $20 = $300 September 9 inventory Purchase September 12 Purchase 10 units @$21 = $210 20 units $22 = $440 September 14 Sales 30 units sold Using the FIFO perpetual inventory method, what is the cost of the ending inventory after the September 14th sale? Multiple Choice O $330 $220 $620