4. The inventory records for Rain 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 @ $1.00 300 units @ $1.10 400 units @ $1.20 100 units @ $1.30 900 units @ $1.50 Determine the amount of cost of goods sold assuming the LIFO cost flow method. a. $1,140 b. $1,040 c. $1,000 d. $940