If two goods are complements:

(A) they are consumed independently.

(B) they are necessarily inferior goods.

(C) a decrease in the price of one will increase the demand for the other.

(D) an increase in the price of one will increase the demand for the other.

The answer is C.

Explanation:

Complementary goods are goods that are consumed together as a pair. They are mostly not consumed alone. If you buy one, you must buy the other. Example, bread and butter.

The answer to the question is C. a decrease in the price of one will increase the demand for the other.

For example, bread and butter are complements. If there is an increase in price of butter, other things remaining equal, there will be a decrease in the quantity demanded of bread. And since the demand of bread has reduced, the demand for its complement, butter too will decrease and vice-versa