Mantle Company's accounting records show the following at the year ending on December 31, 2016: Purchase Discounts $ 16,500 Freight - In 22,100 Purchases 413,000 47,000 Beginning Inventory Ending Inventory Purchase Returns 57,600 15,600 Using the periodic system, the cost of goods sold is Select one: a. $392,400. b. $423,600. C. $403,000. d. $413,600