2. Suppose there are two sources (i.e., A and B) of CO2 emission in the economy for a given year and the total abatement cost (TAC) for the two sources of pollution are given respectively as: TACA TACB = 400 ZA + (ZA) 200 ZB + 3 (ZB) = where TACA and ZA are respectively the total abatement cost and amount of CO2 abated by source A and TACB and Z are respectively abatement cost and amount of CO2 abated by source B. Assume that out of the 240 tones of uncontrolled CO2 emission (i.e., 120 tones each), now the authorities set a total CO2 control target of 100 tones by both firms.