When Designing a Policy to Reduce Polluting Emissions,policymakers Are Unlikely

When designing a policy to reduce polluting emissions,policymakers are unlikely to know with certainty what the marginal cost of abatement is for each firm.If an emissions tax ($t per unit of emissions) is imposed,then policymakers

A) know what the reduction in emissions will be but do not know at what cost.
B) know with certainty what the reduction in emissions will be and at what cost.
C) know the per-unit cost imposed on firms but do not know what the reduction in emissions will be.
D) are uncertain about both the amount of emission reduction and the cost.
E) know with certainty what their tax revenues will be from the emissions tax.