Dr. Kleitman ______. A: has lost so much sleep that he is now suffering from insomnia B: has conducted experiments on sleepwalkers C: has slept more than any other living man of his age D: does not believe that there are any sleepwalkers at all

Which of the following statements is NOT true（） A: Getting off to work with a minimum effort helps save one's energy. B: Dr. Kleitman explains why people reach their peaks at different hours of day. C: Habit helps one adapt to his own energy cycle. D: Children have energy cycles, too.