1. In the diagram above, Plant A is currently polluting 9 units of gunk per day, while Plant B is polluting 6 units of gunk, for a total of 15. To achieve a cost-effective reduction to 9 units total a. regulators could distribute tradeable permits for 7 units per day to plant A. and 2 units per day to Plant B. b. regulators could set a tax equal to $4 per unit of gunk. c. regulators could specify that Plant A reduce emissions to 4 units per day, while plant B reduce emissions to 5 units per day. d. a or b. . a. b or c. I'D