A small mail-order company uses 15,000 boxes a year. The holding cost rate is 20 percent of unit cost per year, and the ordering cost is $30 per order. The following quantity discounts are available. Number of Boxes Price per Box 1,000 to 1,999 1.30 2,000 to 4,999 1.20 5,000 to 9,999 1.18 10,000 or more 1.16 Determine the optimal order quantity. Question 1 options: 5000 10000 2000 1000