The Diagram Below Shows the Marginal Costs of Pollution Abatement

The diagram below shows the marginal costs of pollution abatement for two firms, Firm 1 and Firm 2. FIGURE 17- 5
-Refer to Figure 17- 5. Suppose Firm 1 and Firm 2 are each abating Q3 units of pollution. If the government imposed an emissions tax of $40 per unit of emissions,

A) each firm would abate to Q3.
B) the level of pollution would be optimal.
C) each firm would abate to the same level.
D) Firm 2 would increase abatement beyond Q3 and Firm 1 would abate less than Q3.
E) Firm 1 would increase abatement beyond Q3 and Firm 2 would abate less than Q3.