Choice "C" is correct. Under U.S. GAAP, the only acceptable method of accounting for research and development costs is a direct charge to expense, except for materials, equipment, or facilities that have alternate future uses that are capitalized and depreciated over their useful lives.Choice "a" is incorrect. The only research and development costs that are capitalized under U.S. GAAP are materials, equipment, or facilities that have alternate future uses that are capitalized and depreciated over their useful lives (not necessarily a 5-year period).Choice "d" is incorrect. The only research and development costs that are capitalized under U.S. GAAP are materials, equipment, or facilities that have alternate future uses that are capitalized and depreciated over their useful lives (not a 40-year period).Choice "b" is incorrect. Under U.S. GAAP, the only acceptable method of accounting for research and development costs is a direct charge to expense in the period incurred (except for materials, equipment, or facilities that have alternate future uses that are capitalized and depreciated over their useful lives).