In the Heckscher-Ohlin model, what assumption is made about opportunity costs?

Which of the following statements is true with respect to a tariff on imported cheese?

a. It lowers the price of cheese. b. It lowers domestic cheese producers' profits. c. It creates tax revenues for the government. d. It cannot result in retaliation. e. It increases the amount of foreign cheese sold.

Competitive markets are characterized by

a. a small number of buyers and sellers. b. unique products. c. the interdependence of firms. d. free entry and exit by firms.