Answer: Decomposer
Explanation:
Bacteria feed on the dead and decaying organism, in which they feed on them and obtain energy from them.
It is not a mutual relation because the host cell on which they feed is not alive. They eat the organic matter that is present in environment.
The bacteria and fungi clean the environment in this way. The dead plants and animals are decomposed in the environment and the nutrients get back into the soil.
hence, the correct answer is option B
