The interaction of individual choices

Because a type of fish is on the verge of extinction, the government imposes rules that prohibit fishing in the publicly owned spawning grounds. At first, owners of fishing boats complain about this restriction on where they can fish, but soon they notice that the number of adult fish swimming outside the protected area is much higher than it was before. With the restriction, each fishing boat ends up catching more fish than it did before the restriction was in place.

Which of the following principles of economic interaction best describes this scenario?

A. When markets do not achieve efficiency, government intervention can improve overall welfare.

B. Markets usually lead to efficiency.

C. Markets allocate goods effectively.

D. There is a tradeoff between equality and efficiency.