Given That Different Firms Typically Have Different Costs of Pollution

Given that different firms typically have different costs of pollution reduction,

A) it is clear that only a moral solution can actually achieve pollution reduction.
B) tradable pollution permits will help to reduce the total costs of pollution abatement.
C) the optimal emissions tax is thus easier to compute.
D) there is a role for government to establish absolute limits on pollution.
E) tradable pollution permits will help to reduce the marginal costs of pollution.