In the USA, raw sewage (e. g., wastewater from toilets and baths) poses a threat to public health and the health of ecosystems because it contains . Group of answer choices: a) high levels of ozone that can cause a lot of damage to plants and other living tissues b) very little organic nutrients and very little inorganic nutrients c) disease-causing microorganisms and organic and inorganic elements that can be used as nutrients for naturally-occuring microorganisms living in freshwater d) ecosystems aesbosteos fibers that can be ingested by living organisms lead and mercury.