Concept:Goods are classified by how their demand responds to changes in consumers' income.
Explanation:When money income increases, the demand for normal goods also increases.
This shows a direct, or positive, relationship between income and demand.
Inferior goods have demand that falls as income rises.
Complementary goods and substitutes are classified by their relationship with other goods, not with income.
Therefore, the correct description matches normal goods.
Answer:D. normal goods