Which one of the following groups of animals is correctly matched with its one characteristic feature without even a single exception

The members of class-Chondrichthyes are marine animals with streamlined body and have cartilaginous endoskeleton.
Chordata These possessing a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle and a post and tail for atleast some period of their life cycle.
Mammalia These are a clade of endothermic amniotes distinguished from reptiles and birds by the possession of hair three middle ear bones, mammary glands, and a neocortex.
Reptile These are an evolutionary clade of animals, comprising today's turtles, crocodilians, snakes, lizards and tuatara, their extinct relatives and some of the extinct ancestors of mammals.