Which of the following factors is considered a nonprice determinant of demand?

A nonprice determinant of demand refers to a factor other than the price of the good itself that can shift the demand curve either to the left or to the right. Income is one of the key nonprice determinants of demand because when consumers' income changes, it can significantly affect their purchasing power and willingness to buy goods.

If consumers experience an increase in income, they typically have more money to spend, which can lead to an increase in demand for normal goods. Conversely, if income decreases, the demand for these goods may fall, shifting the demand curve. This relationship highlights how changes in consumer income can influence overall market demand independently of the price of the good.

In contrast, the price of the good directly affects the quantity demanded, as described by the law of demand; the quantity supplied relates to how much producers are willing to sell at various prices; and market equilibrium concerns the point at which supply equals demand, rather than factors that shift demand. Therefore, income stands out as the correct answer, as it strategically influences demand outside of price changes.