Which of the Following Explains Why the Quantity of a Good

Multiple Choice

Which of the following explains why the quantity of a good demanded decreases when its price increases?

A) ​Consumer preferences change when the price of a good changes.
B) ​The nominal income of consumers falls when the price of a good increases.
C) ​Substitutes become relatively cheaper when the price of a good increases.
D) ​Complements become relatively cheaper when the price of a good increases.