Answer:
A gain occurs when the selling price exceeds book value
Explanation:
When an asset depreciates, the loss of value of the asset is reflected in the book value.
For example, if a car has a useful life of four years, by the third year, it will have depreciated by 75%, or in other words, it will have lost 75% of its original value.
For this reason, if the firm manages to sell the depreciable asset for a higher value than its book value, the firm will made a net gain on the asset, because it is earning more from the sale than the value it had stored in the form of the depreciable asset.