Archaea have molecules with reactive side chains in their plasma membrane, so the tails of archaeal phospholipids form covalent bonds with one another. as a result, the plasma membrane is a. less fluidb. more fragilec.  easily disturbedd.  less rigide.  more hydrophobic

Archaea have molecules with reactive side chains in their plasma membrane, so the tails of archaeal phospholipids form covalent bonds with one another. As a result, the plasma membrane is---  less fluid.

Archaea's membranes are made up of glycerol-ether lipids. Its ether bonds are chemically more stable than ester bonds, so it helps archaea to survive in extreme temperatures and extreme pH environments.

the answer is d. chordata