I NEED HELP ON THIS QUESTION ANSWER AS QUICKLY AS POSSIBLE!!

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

the answer is c. altitude. hope this ! #brainiac