Answer:
4. organisms contain peptidoglycan in their cell walls.
Step-by-step explanation:
Archaea are basically just a different category of bacteria separated mainly by DNA differences and their preference for living in extreme environments. The answer is 4 because archaea do not have cell walls made of peptidoglycan.
Why not 1: Both bacteria and archaea are prokaryotic, meaning they lack a true nucleus like eukaryotes have (eukaryotes includes humans!).
Why not 2: Both can use flagella to swim around.
Why not 3: Because archaea are basically a sub-class of bacteria, (they only recently separated them into different kingdoms) it makes sense that they also reproduce by binary fission, which is asexual.