A company will begin stocking an industrial component. Expected annual demand is 4,000 units. The parts can be purchased in one of three price categories: Zero to 399 costs $25.00, 400 to 999 costs $24.75, and 1,000 and over costs $24.50. Ordering cost is $50.00 and annual holding cost is 35 percent of unit price per unit. What order quantity is optimal if the intent is to minimize total annual costs? Defend your answer and show the cost calculations.