Which of the following statements is (are) true? 1. Under group and composite depreciation methods, gains and losses on the disposal of individual assets need not be computed. II. Total depreciation is the fame over the life of an asset regardless of the method of depreciation used. III. Changes in the estimates involved in depreciation, depletion, and amortization require retroactive restatement of financial statements. O II and III O I, II, and III O I and II O l only