To enforce the optimum level of emissions, a government could set an emissions fee, which would be ...

To enforce the optimum level of emissions, a government could set an emissions fee, which would be
A) the dollar value indicated by the intersection of the MSB and MCA curves, and would apply to every unit of pollutants the firm emitted.
B) the dollar value indicated by the intersection of the MSB and MCA curves, and would apply to every unit of pollutants the firm emitted above the standard.
C) the vertical intercept of the MSB curve.
D) the vertical intercept of the MCA curve.
E) the vertical distance between the intercepts of the MSB curve and the MCA curve.