Figure 1. Suppose that the combined abatement for two stationary sources, Firm X and Firm Y, must total0 units. The figure below illustrates the possible allocations of 60 units of abatement between the two firms and shows each firma marginal abatement cost (MAC), which depends on the amount of abatement the firm performs. MACK B C A D E F MAC Polluter X's abatement Ax 60 60 Polluter Y's abatement AY 6) Refer to Figure 1 The total cost for both firms at the costeffective solution is and the excess cost from using a uniform abatement standard instead of the cost effective solution is A) B+D+E+F; B B) D+E+F; A+B+C C A+D+E+F; B+C D) D+E+F; B