Answer: option B) they naturally break down organic matter.
Explanation:
Bacteria are highly beneficial organisms in terms of making use of simple inorganic molecules that could be derived from wastes. They form good examples of chemoautotrophs i.e microorganisms capable of using inorganic molecules such as ammonia, hydrogen, methane or other compounds found in wastewater to produce useful energy.
Thus, in wastewater bacteria are useful as they break down organic matter.
