The correct answer is: Replacement basis.
How much the asset will cost to replace is the best approximation of its worth if it is to continue to be used in the business. Replacement basis will be used if the asset is to be sold or the business broken up. An asset's historic cost won't be a realistic figure if the asset is some years old. Historic cost adjusted for depreciation will be better but depreciation is only an approximation for use and loss of value.
