When free entry is one of the attributes of a market structure, economic profits are:
a. generally driven to zero in long-run equilibrium.
b. generally negative for all firms

The Phillips curve trade-off relationship implies that

A) there is no relationship between inflation and unemployment, at least in the long run. B) the government can fine-tune the economy and generate both the natural rate of unemployment and zero inflation. C) the government can fine-tune the economy and pick the most preferred combination of unemployment and inflation. D) low unemployment can be obtained only by generating rapidly increasing inflation.

The intuition behind the budget constraint is that

A) more options are preferred to less. B) money is the root of all happiness. C) information is power. D) scarcity is avoidable with prosperity.