The correct option is A Ascertainment of true cost of production
Depreciation is an accounting method of allocating the cost of a tangible assets over its useful life. One of the objective of providing depreciation is: Ascertainment of true cost of production. Correct cost of production cannot be ascertained if the depreciation is not charged to the fixed assets. Thus, it is necessary to include amount of depreciation in the calculation of cost of each product.