When the Marginal Costs of Pollution Abatement Equal the Marginal

When the marginal costs of pollution abatement equal the marginal benefits of pollution abatement,

A) any further reductions in pollution will lower net social benefits.
B) pollution has been entirely eliminated.
C) any further reductions in pollution will continue to increase net social benefits.
D) then firms are likely to increase output.
E) then firms are likely to decrease output.