The Desirable Level of Output in a Perfectly Competitive Market

Multiple Choice

The desirable level of output in a perfectly competitive market if there exists a detrimental externality is

A) the point at which MSC curve intersects the marginal revenue curve.
B) the point at which MSC intersects the MPC.
C) the point at which MSC intersects the marginal private benefit curve.
D) the point at which marginal revenue curve intersects the MPC.