Correct Response: C. Eutrophication is a process in which the introduction of excessive nutrients into an aquatic system leads to excessive plant and algae growth. Agricultural fertilizers or other nitrogen-rich chemicals are often a source of the excess nutrients. When the plants and algae die, they are decomposed by aerobic organisms that reduce the oxygen levels in the aquatic system. A is incorrect because acid rain is not involved in eutrophication. In fact, acid rain would hinder plant and algae growth rather than promote it. B is incorrect because heavy metals can be detrimental to plants and algae. D is incorrect because eutrophication results in a shortage in the supply of oxygen in the aquatic system.
