Applying the Concept of Opportunity Cost to the Pollution of a Lake

Applying the concept of opportunity cost to the pollution of a lake, an economist probably would conclude that:

A) all pollution in the lake should be eliminated regardless of cost.
B) no pollution in the lake should be eliminated regardless of benefit.
C) pollution should be eliminated as long as the benefit from a cleanup exceeds the opportunity cost.
D) pollution should be eliminated as long as the opportunity cost of a cleanup exceeds the cost of the resources required for the cleanup.