Answer: The correct answer is-
They have different types of cell walls and cell membranes.
Archaebacteria and Eubacteria are the two distinct domains of prokaryotes ( single celled organisms that are devoid of nucleus and membrane bound organelles) according to the Carl Woese three domain system of classification.
Domain Archaebacteria consists of the primitive forms of bacteria that live under extremely harsh environmental conditions ( such as hotsprings, volcanic eruptions).
They have different biochemical composition in their cell wall.
For instance, Archaebacteria do not have peptidoglycan in their cell wall, and have ether-liked lipids ( which provides them advantage to survive under harsh conditions), which are present in the form of branched chains.
Eubacteria have peptidoglycan in their cell wall, and they have ester-linked lipids, which are present in straight chain. They live in moderate climatic conditions.