The Diagram Below Shows the Marginal Cost of Abatement for Each

The diagram below shows the marginal cost of abatement for each of two firms, A and B. Each firm is initially abating Q0 units of pollution. FIGURE 17- 6
-Refer to Figure 17- 6. Suppose that a system of tradable pollution permits is introduced into this market and the equilibrium permit price is p*. Firm B will buy permits from Firm A because

A) its total cost of abating less (areas 1+2+3) exceeds the cost of buying the permits (areas 2+3) .
B) Firm B can buy the permits at a lower price than Firm A.
C) its total savings from abating less (areas 1+2+3) exceed the cost of buying the permits (areas 2+3) .
D) Firm B has lower costs of pollution abatement than Firm A.
E) its total savings from abating less (areas 1+2+3) exceed the total costs of Firm A abating more (area 6) .