The correct answer is: Phytoplankton
Phytoplankton is an autotrophic organismthat lives in water and it is incapable of swimming against the water current. They can be found in all water systems, oceans, seas and freshwater basin ecosystems. Phytoplanktons are prokaryotic, usually single-celled organisms, bacteria or protists. The most common kinds are cyanobacteria, dinoflagellates, green algae, and coccolithophores.
