Answer: Option A.
Herbivores
Step-by-step explanation:
It is Herbivores because they are group of organism that eat plants and they have cecum. The cecum store good material and contain bacteria. These bacteria help to breakdown to breakdown cellulose into smaller particles where it is easily absorbed.
The bacteria benefit by feeding on the waste reminants and receive accomodation and the herbivores benefit and receive help from the bacteria because the bacteria help them to digest cellulose.