Which of the following statements about the depreciable base of a fixed asset is true?
a. To calculate MACRS depreciation, the depreciable base must first be determined
b. A company should always depreciate all of an asset's cost without regard to the residual value
c. The depreciable base is not used to calculate depreciation under the units of production method
d. The depreciable base is calculated by subtracting residual value from asset cost.