P (dollars) Q (units) Consider the following perfectly elastic demand curve for good X. At a price of P3, quantity demanded O is 0 units 0 is? units O cannot be determined Willingness to pay represents: O the point at which the benefit that a person will get from a good is equal to the benefit of spending the money on the next best alternative. O the opportunity cost of a good. O the buyer's reservation price. O All of these represent willingness to pay. When a market is efficient: O there is no exchange that can make anyone better off without someone becoming worse off. O a central planner must be involved. O total surplus is zero. O an increase in price will reduce the deadweight loss