Answer:
B
Step-by-step explanation:
One of the problems in economics is the allocation of goods in the presence of externalities. When externalities are present allocation of goods in private market won't be efficient because private parties won't internalize them and would arrive to an inefficient outcome. For many years this was an argument in favor of government intervention.
However, Ronald Coase showed that assigning property rights of the externality to one of the private parties (no matter which one) would result in an efficient outcome. This is because the parties with the property right would then internalize the cost. Then in the bargaining process private parties would reach an efficient outcome without the intervention of the government.