Common resources tend to be overused because:

A) individuals tend to ignore the cost to others of their use of the resource.
B) the individual marginal cost is greater than the marginal social cost.
C) common resources are nonrival and nonexcludable.
D) the marginal cost of allowing one more unit of consumption is zero.

Common Resources

Goods that are non-excludable and rivalrous, meaning they are available to all but can be depleted by overuse.

Marginal Social Cost

This refers to the entire cost society bears for the production of an additional unit of a good, including both private costs borne by producers and external costs absorbed by others.