Choose the Statement That Is Incorrect

Choose the statement that is incorrect.

A) Resources are used efficiently when marginal social benefit equals marginal social cost.
B) Competitive equilibrium achieves an efficient outcome.
C) Competitive equilibrium maximizes the gains from trade.
D) When firms in perfect competition are away from long-run equilibrium,either entry or exit is taking place and the market is still efficient.
E) Producer surplus is maximized at the competitive equilibrium.