A. Microscopic floating organisms – Plants and animals.
B. bottom dwelling aquatic organisms
C. large plants in water
D. none
Plankton are the diverse collection of organisms that live in large bodies of water and are unable to swim against a current. The individual organisms constituting plankton are called plankters. They provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales.