Economists make a distinction between changes in quantity demanded and changes in demand:

A.) Because the supply curve shifts whenever there is a change in demand.
B.) Because the demand curve shifts whenever there is a change in quantity demanded.
C.) To distinguish a movement along a demand curve from a shift of the demand curve.
D.) To distinguish a surplus from a shortage.

ANSWER

C.) To distinguish a movement along a demand curve from a shift of the demand curve.