Price increases always reduce economic efficiency.

Suppose the price of crude oil drops from $150 a barrel to $120 a barrel. The quantity bought remains unchanged at 100 barrels. The coefficient of price elasticity of demand in this example would be

A) -0.5. B) infinity. C) -1.0. D) 0.

The firm in a perfectly competitive industry

a. is a price-taker b. is a price-maker c. attempts to differentiate his/her product through advertising d. will earn an economic profit in the long run e. can charge any price it wishes