Carl Woese proposed the classification of the organisms in three kingdoms, Archaebacteria, Eubacteria and Eukaryota, which were later called the domains. The archaebacteria are the group which is comprised of the primitive prokaryotic organisms like methanogens. These are unicellular, anaerobic and autotrophic prokaryotes. The cell wall lacks peptidoglycan and can convert carbon dioxide and hydrogen into methane gas. The hydrogen serves as an electron donor for the reduction of carbon dioxide.
Therefore, the correct answer is option D.