Which of the following statements about the last-in, first-out (LIFO) conformity rule is true? a.If a company elects to use LIFO inventory valuation for tax purposes, then it must also use LIFO for external financial reporting. b.Manufacturing inventories are to be disclosed compulsorily in the notes to the financial statements if the LIFO method is used. c.When finished goods are sold, their costs are to be transferred to cost of goods sold on the income statement if the LIFO method is used. d.If identical units of inventory are acquired at different unit costs during a period, it is necessary to determine the items' cost using the LIFO method when they are sold.