Solution:
Note that domain B can refer to Archea organisms. These organisms can be extremophiles, that is, they can live in extreme environments. In fact, Archaea live everywhere on Earth, including extreme environments. Although Bacteria and Archea may look similar, archaea have many characteristics that distinguish them from bacteria. For example, the cell walls of archaea are different from those of bacteria. While bacteria have cell walls made up of the polymer peptidoglycan, most archaea do not have peptidoglycan in their cell walls.
So that, we can conclude that the correct answer is:
D) peptidoglycan
