The inventory records for Ramirez Co. reflected the following Beginning Inventory @May 1 First Purchase @May 7 Second Purchase @ May 17 Third Purchase @ May 23 Sales @ May 31 200 units @ $2.00 300 units @ $2.20 500 units @ $2.30 100 units @ $2.40 900 units @ $3.90 Determine the amount of ending inventory assuming the FIFO cost flow method. a. $480 b. $470 C. $400 d. None of the above