Answer:
A. Algae growth is high
Step-by-step explanation:
Substances that contains high concentration of nitrates, phosphates etc add nutrients to the water body. This is because organisms like ALGAE consider these compounds nutrients needed for their growth and development. The process whereby these nutrients becomes excessive in a water body is referred to as EUTROPHICATION.
Eutrophication of a water body i.e excessive nutrients like nitrates in a water body like the North Carolina waters being described in this question will lead to rapid and excessive growth of algal species. This increase in algal growth can cause the water body to be low in oxygen content and ultimately become inhabitable by living organisms.