4. The merchandise inventory data for an item for September are: Sept. 1Beginning Inventory 4 Sold 10 Purchased 30 Purchased 20 units at S19.00 per unit 0 units 30 units at $20.00 per unit 20 units 10 units at $21.00 per unit Using the perpetual system, costing by the first-in, first out (FIFO) method, what is the total cost of the merchandise sold for September? a) $610.00 b) $600.00 c) $590.00 d) $580.00