Suppose Twenty Neighbors Share a Park

Suppose twenty neighbors share a park.One of the neighbors,Al,leaves trash in the park.This bothers the other neighbors.According to Coase's theorem,assigning the property rights to the park to Al

A) will achieve the socially optimal quantity of trash.
B) will result in zero trash being dumped in the park.
C) might still not achieve the social optimum since coordinating the other nineteen neighbors can be costly.
D) is unfair.