American union membership as a percentage of the total nonfarm labor force reached its peak in

The minimum-cost output is the quantity corresponding to the minimum point of the:

a. marginal cost curve. b. marginal product curve. c. average variable cost curve. d. average total cost curve.

The perfect competitor has a perfectly elastic demand curve

A. only in the short run. B. only in the long run. C. in both the short run and the long run. D. in neither the short run nor the long run.