The marginal social benefit of a good that exhibits positive externalities is ( Greater or Less than ) the private social benefit of that good. Why?
A. When a trade causes positive externalities, the marginal social benefit equals the marginal private benefit minus the costs incurred by third parties not involved in the trade.
B. When a trade causes positive externalities, the marginal social benefit equals the marginal private benefit plus the benefits received by third parties not involved in the trade.
C. When a trade causes positive externalities, the marginal social benefit equals the marginal private benefit plus the costs incurred by third parties not involved in the trade.
D. When a trade causes positive externalities, the marginal social benefit equals the marginal private benefit minus the benefits received by third parties not involved in the trade.