A firm's inventory planning period is one year. Its inventory requirement for this period is 1,600 units. Assume that its acquisition costs are 50 per order. The carrying costs are expected to be $ 1 per unit per year for an item. The firm can procure inventories in various lots as follows: (i) 1,600 units, (ii) 800 units, (iii) 400 units, (iv) 200 units, and (v) 100 units. Which of these order quantities is the economic order quantity