Suppose That Most Consumers Consider Ice Cream and Frozen Yogurt

Suppose that most consumers consider ice cream and frozen yogurt to be substitutes for one another. How is the market for ice cream affected by an increase in the price of frozen yogurt?

A) The demand for ice cream increases.
B) The quantity of ice cream demanded increases, but the demand is unchanged.
C) The supply of ice cream decreases.
D) The quantity of ice cream supplied decreases.