Factory a Can Reduce Emissions at a Cost of $400

Factory A can reduce emissions at a cost of $400 per ton. Factory B can reduce emissions at a cost of $100 per ton. In a system in which the government issues transferable pollution right at a price of $200 per ton:

A) Factory A can profit from selling its pollution rights to Factory B.
B) Neither firm can profit from selling its pollution rights to the other.
C) Factory B can profit from selling its pollution rights to Factory A.
D) Both firms have an incentive to sell pollution rights.