A common characteristic of all vertebrates without exception is (a) the division of body into head, neck, trunk and tail (b) their body covered with an exoskeleton (c) the possession of two pairs of functional appendages (d) the presence of welldeveloped skull.
Option D The subphylum vertebrata or craniata have a well developed central nervous system that is differentiated into brain and spinal cord. Brain is protected by a brain box called cranium, so they are also called as craniata.
