Given the following data, calculate the cost of ending inventory using the average cost method. (Round any intermediary and final answers to two decimal places) Date Item Unit 1/1 Beginning inventory 60 units at $30.00 per unit 3/5 Purchase of inventory 20 units at $20.00 per unit 5/30 Purchase of inventory 10 units at $12.00 per unit 12/31 Ending inventory 20 units O A. $413.40 O B. $120.00 OC. $515.60 OD. $400.00