Question 9 (Mandatory) (1 point) The income elasticity of demand is the ratio of the percentage change in income to the percentage change in quantity demanded. O measures the change in income necessary for a given change in quantity demanded. C measures the responsiveness of quantity demanded to changes in income. O measures the responsiveness of income to changes in quantity demanded. Question 10 (Mandatory) (1 point) Sue is maximizing her utility. Her MUx/ Px = 10 and MUy = 40. Then the price of Y must be O $ 1. O $ 4. $10. $40