13. When governments employ cost-benefit analysis to help them decide whether to provide a public good, measuring benefits is difficult because

a. one can never place a value on human life or the environment.

b. respondents to questionnaires have little incentive to tell the truth.

c. there are no benefits to the public because a public good is not excludable.

d. the benefits are infinite because a public good is not rival in consumption and an infinite amount of people can consume it at the same time.