Which of the following is true for a monopoly?

When economists use the term "big tradeoff" when discussing efficiency they are referring to the tradeoff between

A) external costs and external benefits. B) marginal cost and marginal benefits. C) producer surplus and consumer surplus. D) efficiency and fairness. E) deadweight loss and producer/consumer surplus.

In monopolistic competition, excess capacity results from

A) the presence of a large number of buyers. B) the mobility of firms into and out of the industry. C) imperfect information about price. D) product differentiation.