Which of the following is not a potential source of monopoly?

Based on the theory of comparative advantage, nations maximize their well being when they

A) create more jobs. B) allocate resources more efficiently. C) increase trade surpluses. D) increase exports.

Under long-run perfect competition, which of the following are the same (equal) at all levels of output?

a. Price and marginal cost. b. Price and marginal revenue. c. Marginal cost and marginal revenue. d. All of these.