By emphasizing that adaptation is a common human trait, paragraph 3 is attempting A. to show that babies learn to walk, and so does everyone else. B. to show that all of us speak the same language, but with different accents. C. to show that there is nothing abnormal or unduly difficult in facing changes associated with aging. D. to show that growing old is just like learning to talk and walk for the first time. E. to prove that infants learn to talk in the same way as older people.