Question

When consumers purchase cell phones, they also often purchase a protective case to take care of the cell phone. As the price of a cell phone rises, the demand for a protective case shifts to the left. This means cell phones and a protective case are Choose one:
A. substitutes
B. inferior goods
C. complements
D. normal goods

Answer 1

Answer: Complements

                                 

Explanation: In simple words, complement goods refers to those goods which are used together for example -  petrol and petrol car. These goods have negative elasticity of demand, means when the price of one increases the demand for the other decreases.

Hence from the above we can conclude that phone and phone case is an example of complementary goods.o the other decreases.