The equivalent annual cost method is useful in determining: A. the annual operating cost of a machine if the annual maintenance is performed versus when the maintenance is not performed as recommended. B. the tax shield benefits of depreciation given the purchase of new assets for a project. C. operating cash flows for cost-cutting projects of equal duration. D. which one of two machines to acquire given equal machine lives but unequal machine costs. E. which one of two machines to purchase when the machines are mutually exclusive, have different machine lives, and will be replaced once they are worn out.