Answer:
Book Value
Step-by-step explanation:
Depreciation refers to fall in the value an asset as a result of normal wear and tear or due to efflux of time.
Depreciation is calculated using the following formula:
Depreciation expense per annum =

When, a company revises an estimate such as salvage value or remaining useful life of the asset, depreciation expense would be recomputed using the following formula:
Depreciation expense =

wherein, Book Value = Original Cost - Accumulated Depreciation till date