Which of the following types of organisms uses hydrogen sulfide for reducing power?

purple sulfur bacteria
algae
prochlorophytes
heliobacteria
cyanobacteria

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.

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.