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If the cost of an item of inventory is $55 and the current replacement cost is 568 , the amount included in inventory occording to the lower-of-cost-or-market method is a. $123 b. 513 c. 568 d. $55 The primary difference between a periodic and perpetual inventory system is that a periodic system a. provides an easy means to determine inventory shrinkage b. determines the inventory on hand only at the end of the accounting period c. keeps a record showing the inventory on hand at all times d. records the cost of the sale on the date the sale is made