As productivity in the manufacturing sector increases, the service sector must keep pace or it will become more expensive in the long run

Which of the following statements best describes trade-offs?

a. With a trade-off, it is necessary to give up some of one good to gain more of the other good. b. Trade-offs are not determined by the relative prices of the goods. c. A trade-off is always represented by a straight vertical line. d. A trade-off is always represented by a straight horizontal line.

Average variable costs are minimized when:

A. marginal costs begin to increase. B. marginal costs begin to decrease. C. marginal cost is greater than average total cost. D. marginal cost equals average variable cost.