B) the decay of once-living things
Hope this helps have a great day!
Water quality testing would be the best approach.
DNA, cell membrane, cytoplasm, and ribosomes.
Both prokaryotic and eukaryotic cells have structures in common. All cells have a cell membrane, ribosomes, cytoplasm, and DNA. The cell membrane, or plasma membrane, is the phospholipid layer that surrounds the cell and protects it from the outside environment.