Which one of the following statements concerning periodic and perpetual inventory systems is correct? Select one: O a. Periodic systems indirectly calculate the cost of goods sold O b. Perpetual systems records cost of goods sold at the end of each accounting period Oc. Periodic systems provide better control over inventories O d. Periodic systems continuously track the balances of each item kept in stock Oe. Perpetual systems don't maintain a detailed record of inventory on hand