A Downward- Sloping Marginal Benefit Curve for Pollution Abatement Means

A downward- sloping marginal benefit curve for pollution abatement means that

A) the costs of pollution decrease as further amounts are abated.
B) the marginal cost of pollution reduction will always exceed the marginal benefit.
C) there are decreasing incremental benefits to be realized from additional increments of pollution abatement.
D) society views additional increments of pollution abatement as unnecessary.
E) it is impossible to know the benefits from additional increments of pollution abatement.