When a motorist speeds down the road at well above the posted limit, economists believe that the principle of ____ may be directing his actions

The above figure shows four different markets with changes in either the supply curve or the demand curve. Which graph best illustrates the market for typewriters after technological advances in computerized word-processing software occur?

A) Graph A B) Graph B C) Graph C D) Graph D

Jonathan likes to consume pizzas and burgers. If both the goods have diminishing marginal utility, then Jonathan's indifference curve is likely to be _____

a. a straight line b. downward sloping c. L-shaped d. U-shaped