Which of the Following Statements Describes the Coase Theorem

Which of the following statements describes the Coase Theorem?

A) If bargaining is costless, and property rights are clearly established and enforced, then externality problems can be solved through private bargaining.
B) Even if bargaining is not costless, and property rights are unclear, externality problems can be solved through private bargaining.
C) If the marginal benefit of a good exceeds the good's marginal cost, more of it should be produced.
D) Elimination of an externality is possible only when the marginal benefit of a good is no higher than its marginal cost.