The Optimal Amount of Pollution Abatement Is Generally Less Than

The optimal amount of pollution abatement is generally less than 100%.Complete (100% ) abatement would be optimal if

A) the marginal cost of abatement is positive but less than the marginal benefit of abatement.
B) the marginal cost of abatement is always zero.
C) the marginal cost of abatement exceeds the marginal benefit of abatement at all levels of abatement.
D) the marginal benefit of abatement is zero.
E) none of the above - we cannot even imagine a situation in which complete abatement would be optimal.