Common resources tend to be overused because: common resources are nonrival and nonexcludable. the individual marginal cost is greater than the marginal social cost. individuals tend to ignore the cost to others of their use of the resource. the marginal cost of allowing one more unit of consumption is zero.

a.) individuals tend to ignore the cost to other of their use of the resource.

Explanation:

A common resource is the one that is not owned by anyone and that gives benefits to the whole society like water. These resources have a problem that is that everyone uses them causing damage to the others as they are not able to get the benefits of them. However, people are not aware of this damage that their use of the resources generate to everyone. According to this, the answer is that common resources tend to be overused because individuals tend to ignore the cost to other of their use of the resource.

individuals tend to ignore the cost to other of their use of the resource

Explanation:

Common resource are resources such as water or pasture, parks or nature preserves, certain natural resources (like the fish in the sea) that is not owned by anybody in particular and nobody can lay exclusive claim to it.

Common resource provides users with very tangible benefits but nobody in particular can claim to own them.

Based on the fact that anybody can enjoy the use in common, there is often risk of over consuming them and the shortage to deficiency of common resources is a big concern.

These is a problem that is that everyone uses these resources causes damage to others using them because they are unable to enjoy these benefits also. But, people do not know of this damage that their use of the resources available to everyone is obstructing the some other people from benefitting from it.

Hence, the option of individuals tending to ignore the cost to other of their use of the resource is correct answer to why common resources are often being overused.