Which one of the following statements concerning periodic and perpetual inventory systems is correct? Select one: O a. Perpetual systems don't maintain a detailed record of inventory on hand O b. Periodic systems provide better control over inventories Oc. Perpetual systems record cost of goods sold at the end of each week O d. Periodic systems records cost of goods sold at the end of each accounting period O e. Periodic systems records cost of goods sold after each sale