18. Marsman Co. has determined the following for a given year: Economic order quantity (standard order size) 5,000 unitsTotal cost to place purchase orders for the year P40,000Cost to place one purchase order P 100Cost to carry one unit for one year P 4 What is Marsman's estimated annual usage in units?A. 1,000,000 B. 2,000,000C. 500,000D. 1,500,000