Answer: The correct answer is- B)They are single cells that lack a nucleus and tend to live in extreme conditions.
Archaebacteria are the oldest life forms, which are found on earth. They are unicellular ( made up of one cell) prokaryotes ( lacking nucleus and membrane bound subcellular organelles) belonging to the kindom, Archea. They are found in extremely harsh environmental conditions such as hotsprings, boiling mud surrounding volcanoes.
Example- Methanogens, halophiles.
Thus, option B) is the right answer.
