it is fair to say that monetizing the benefits of environmental improvements is challenging. some researchers have therefore argued that policymakers should themselves determine the goals of environmental policies in terms of how much pollution abatement should be required, and then incentive-based environmental policy instruments should be used to achieve these goals in a cost-effective manor. examples of such incentive-based policies include all of the following except: select one: a. taxes on pollution. b. tradeable permits. c. subsidies to abatement. d. command-and-control policies.