Which of the following is NOT a focus of the study of economics?

The primary area of growth in the modern U.S. economy is

a. the manufacturing sector. b. the agricultural sector. c. the service sector. d. the market for U.S. exports.

The output level at which a firm's long-run average total cost is minimized is known as its

a. profit-maximizing output level b. long-run marginal cost c. minimum efficient scale d. revenue maximization level e. equilibrium cost structure