What happens when wages are set above the equilibrium level by law?

Sergio's rentals of Blu-ray movies increase by 10 percent when her income increases by 30 percent. Based on this information, we know that for Sergio, Blu-ray movies

A) are complements. B) are substitutes. C) are inferior goods. D) have an inelastic demand. E) are normal goods.

In economic analysis marginal analysis is used to:

a. make an either-or decision. b. determine which costs are sunk costs. c. decide how much of something is the optimal amount. d. convince others that the costs of a certain activity do not matter