Which of the Following Statements About Pollution or Pollution Control

Which of the following statements about pollution or pollution control is TRUE?

A) A nationwide uniform tax on emissions is the appropriate way to reduce pollution levels.
B) A tax to reduce pollution levels should be based on the economic damages rather than on the absolute amount of pollution.
C) Private costs of pollution usually exceed social costs.
D) The optimum amount of pollution abatement is where the total benefits of pollution abatement equal the total costs of pollution abatement.