Which of the Following Statements Concerning Pollution Is Correct

Which of the following statements concerning pollution is correct?

A) Economic efficiency requires that pollution be completely eliminated.
B) Economic efficiency dictates that the optimal amount of pollution arises at the point at which price equals private marginal cost.
C) Pollution should be reduced to the point at which the marginal benefit from further reduction equals the marginal cost of further reduction.
D) Pollution should be reduced to the extent necessary to return production to the production possibilities frontier.