The answer is: A
Explanation
The correct option is A: Income from capital gains.
This is because the gain arising from the sale of a residential house is considered as a capital asset under section 2 (14) of the Income-tax Act, 1961. Capital gains are computed by deducting the cost of acquisition and the cost of improvement from the full value of consideration received or accruing as a result of the transfer of the capital asset. Since Mr. Kapoor sold the house within 24 months of purchasing it, the gain is classified as a short-term capital gain and is taxable at the normal rates applicable to his income slab. Income from house property, income from profits and gains from business or profession, and income from other sources are not applicable in this case, as they are meant for different types of income sources.