Bikes and Roller Blades Are Substitutes

Multiple Choice

Bikes and roller blades are substitutes.Marginal utility theory predicts that when the price of a bike rises,the quantity of bikes demanded

A) decreases and the demand curve for roller blades shifts rightward.
B) decreases and the demand curve for roller blades shifts leftward.
C) decreases and a movement occurs down along the demand curve for roller blades.
D) increases and the demand curve for roller blades shifts rightward.
E) increases and the demand curve for roller blades shifts leftward.