Solve clearly..

1. The marginal cost to society of fertilizer runoff is described by the equation M CP = 3Q 200, Where Q is measured in ppm of runoff. The abatement cost is estimated by regulators to be MA C8 = 360 Q, however, unbeknownst to the regulators, the actual abatement costs are MAC = 400 Q. In this case, is it better if the regulators use a quantity, or a price mechanism to mitigate the externality