43. Addison, Inc. uses a perpetual inventory system. The following is information about one inventory item for the month of September: Sept. 1 Inventory 20 units at $20 Sale 10 units 10 Purchase 30 units at $25 17 Sale 20 units 30 Purchase 10 units at $30 4 (a) If Addison uses FIFO, the cost of the ending merchandise inventory on September 30 is a. $800 b. $650 c. $750 d. $700