By anaerobic process,the cow dung is used to produce

The microorganism used in the production of biogas is:

In biogas production,the decomposition of dung to produce gas is carried out by which of the following?

The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals include the:

Assertion $A$: Herbivores release methane gas into the atmosphere.
Reason $R$: Herbivores consume a cellulose-rich diet.
Which option is correct for Assertion $A$ and Reason $R$?

What is the group of bacteria responsible for the production of biogas called?