An exchange rate system under which currencies are allowed to fluctuate with frequent interventions by central banks is called a

In the long run, a monopolistically competitive firm has market power but earns no profit.

Indicate whether the statement is true or false.

When the efficient quantity of output is produced

A) the marginal social benefit of the last unit produced is equal to the marginal social cost of the last unit produced. B) the sum of consumer surplus and producer surplus is maximized. C) resources are used in the activities in which they are most highly valued. D) All of the above answers are correct.