Which of the Choices Correctly Describes a Cap-And-Trade Policy, but Not

Which of the choices correctly describes a cap-and-trade policy, but not a carbon tax policy?

A) The policy is designed to phase out fossil fuels and develop alternative energy resources.
B) The policy may result in displacement of people that are dependent on fossil fuel industries.
C) The policy is a market mechanism that creates an incentive for firms to reduce pollution.
D) The policy requires power plants and vehicles to use emissions-reduction technologies.