When an asset becomes impaired how do we record this?

A$.$ The asset value is reduced on the balance sheet and the initial cost of the asset is written off as an impairment cost

B$.$ The asset value is reduced on the balance sheet and the difference between the fair value of the asset and its current book value written off as an impairment cost

C$.$ The asset value is reduced on the balance sheet and instead recorded as a liability.

D$.$ None of the above describes the correct accounting procedure for an impaired asset.