If average cost rises as a firm increases its output level,

In 18th century Europe, governments gave guilds legal authority to limit production of goods. How did this authority either obstruct or improve the market mechanism?

A) It obstructed the market mechanism because with one more party having to coordinate activities (the guilds) there were delays in getting the products to consumers. B) It improved the market mechanism because the government's actions provided the correct set of signals to the market so that producers can adjust their output to better meet the needs of consumers. C) It improved the market mechanism by making it more efficient because the guilds were able to quickly identify and rectify any market shortages and surpluses. D) It obstructed the market mechanism because the guild's actions prevented the forces of demand and supply from coordinating the self-interested decisions of producers and consumers.

Which of the following statements is true of the tax on gasoline?

a. The cost of collecting a gasoline tax outweighs the revenues raised by the tax. b. It is preferred to tolls as the best solution to road congestion. c. It discourages driving on noncongested roads, even though there is no congestion externality for these roads. d. Both b and c are correct.