Which Situation Best Describes the Tragedy of the Commons

Which situation best describes the tragedy of the commons?

A) A fisherman uses his net to catch a large quantity of fish.
B) Increasing amounts of pesticides need to be used over time to maintain the same effect on pests.
C) An oil pipeline leaks.
D) Sustainable forestry practices are applied to a plot of land in the rainforest.
E) Herders put too many sheep in a public field because they think "If I don't use this available resource, someone else will."