One of the students in your study group is struggling with the idea that mammals and vertebrates are separate designations. To illustrate the two terms, you describe an animal that has the expected mammalian characteristics. What should you include in your description of this animal that would make it clear that the animal is specifically a mammal and not just a vertebrate? (Check all that apply)
(A) Hair
(B) Notochord at some point during development
(C) Cranium
(D) Four limbs
(E) specialized teeth