The correct option is D All of the above
Introduction to decomposers
Decomposers are organisms that depend on dead and decayed organisms for nutrition. They metabolically break down the animal excreta and dead remains of plants and animals and release simple organic and inorganic substances into the environment.
Decomposers of the pond ecosystem
Decomposers of a pond ecosystem include microscopic organisms such as bacteria, flagellated protists, and fungi.
Final answer
(D) All of the above