Which of the following statements accurately describes the concept of tax depreciation in accounting?

A$)$ Tax depreciation allows businesses to deduct the entire cost of an asset in the year it is acquired.

B$)$ Tax depreciation is based on the estimated useful life of an asset and allows businesses to spread the cost of an asset over its useful life for tax purposes.

C$)$ Tax depreciation is determined by the fair market value of an asset at the end of its useful life.

D$)$ Tax depreciation is calculated based on the market value of an asset at the time of its acquisition.