In the Following Paragraph, Fill in the Blanks (Indicated by Numbers)

In the following paragraph, fill in the blanks (indicated by numbers) with either Archaea (A), Bacteria (B), or Eukaryotes (E). Your answer would be a three-letter string composed of letters A, B, and E only, e.g. ABE.
"Methanococcus jannaschii is an anaerobic thermophilic microbe that belongs to the domain ... (1) and is found in extreme environments such as hydrothermal vents. It lives at temperatures near the boiling point of water and at pressures over 200 times higher than at sea level. Its genome sequence, identified in 1996, revealed that most of its metabolic processes are similar to those in ... (2), while its genetic machinery is more similar to that of ... (3)."