A) The change in the price of a good that alters the quantity supplied.
B) The change in quantity demanded resulting from a change in the price of a good, holding real income constant.
C) The change in the price of a good that alters the consumer’s real income and, thus, the quantity demanded.
D) The responsiveness of quantity demanded to a change in the price of a substitute good.
For Explanation Click Here:
The income effect refers to the change in a consumer’s purchasing power when the price of a good changes. If a good’s price decreases, the consumer can afford to buy more, effectively increasing real income and demand for the good.