Annual demand of a product is 2,000. It will cost $60 to place an order. The holding cost is estimated as $6 per unit per year. The purchase cost is $5 per unit is the order quantity is less than 500 units. The supplier gives a discount of 10% if the purchase quantity is 500 or more. How many units should be ordered? A. 200 B. 350 C. 500 D. Not enough data to answer this question.