Answer:
There are three classes of Archaea are Methanogens, Halophils and Thermo acidophills
Explanation:
Methanogens : They produce methane gas a waste product of their digestion or process of making energy
Halophiles: They live in salty environments
Thermoacidophilles: They live in hot acidic terrestrial environments.They are Crenarchaeota belonging to the Acidilobales and the Sulfolobales.