In bacterial cell walls a. peptides form crosslinks between polysaccharides b. polysaccharides form nonspecific mixtures with proteins c. oligosaccharides form crosslinks between proteins d. polysaccharides are hydrogen bonded together

the correct option is A "peptides form crosslinks between polysaccharides"

Explanation:

The bacterial wall of bacteria is made up of a complex peptide that is called peptidoglycan, which in turn is intertwined with polysaccharides and many more structures such as protein, this wall is confined or has the function of being able to protect the osmotic balance of the bacteria so that it does not go into failure and does not lose vitality. If the wall breaks, the bacteria goes into osmotic shock and dies, which is why this was a great discovery, because although it is very difficult to pass through antibiotics or antiseptics, once the porification of this wall is generated, the osmotic balance is lost and bactericidal power is acquired.

the fossil record provides evidence of a common ancestor to many species.