If a long-lived asset's remaining expected future value falls below its net book value,the asset is considered to be a/an

A) extraordinary item.
B) discontinued operation.
C) valuable asset.
D) impaired asset.

When the net book value of a long-lived asset exceeds its expected future value, it is considered to be impaired. This means that the asset's carrying amount should be adjusted down to its estimated fair value to reflect its reduced usefulness or marketability. The impairment loss should be recognized in the income statement as a separate expense.