Answer:
The best option is letter A. imposing a tax per unit of pollution generated.
Step-by-step explanation:
According to the instructions, people usually exploit opportunities to make themselves better off. That means people are motivated by saving or making money. Since that is our premise, the best option is letter A. If a tax per unit of pollution generated is imposed, people will be more careful. They will try harder to pollute less, since polluting more means spending their money. The other options deal with ethics and environmental awareness. Even though they are not ineffective, they don't work well with the premise we were given.