Suppose That an Industry Emits a Chemical That Pollutes Ground $P = 60 - Q$

Suppose that an industry emits a chemical that pollutes ground water. Without considering the effects of the pollution, the industry has a marginal private cost curve of MPC = Q+30. The market demand curve is $P = 60 - Q$ , while the marginal social cost curve is MSC = 2Q + 30. What level of emissions fee would achieve the socially optimal level of output?

A) $54.
B) $32.
C) $12.
D) $10.