What Role(s) Do Archaeons Play in the Rumens of Cows

Multiple Choice

What role(s) do archaeons play in the rumens of cows?

A) Archaeons produce methane, which contributes to the acidic environment of a cow's rumen.
B) Archaeons out-compete bacteria in the rumen, effectively preventing infections.
C) Arachaeons help to digest plant material in the rumens of cows.
D) Archaons produce methane, contributing to the acidic environment, and help digest plant material.