The correct option is C 1- producers, 2- consumers, 3- decomposers
Organisms which produce food by photosynthesis are known as producers. For example, grass, cyanobacteria, phytoplanktons, etc. Algae and phytoplanktons are called aquatic producers as they are a part of aquatic ecosystem.
The organisms which consume green plants or other animals are consumers. For example, animals like lions, cows, deer and rats.
Organisms which break down the dead and decaying remains of living organisms are decomposers. E.g. bacteria and fungi