[单选,材料题] According to the author，which of the following most interested the researchers?
According to the passage，which of the following is NOT true?
A . The mice that started dieting in old age．
B . 27 of those 46 0ld genes that continued to behave like young genes．
C . Calorie restriction that works in people．
D . Dieting that makes sure a drug is effective．