问题详情

According to the passage, we do not know whether humans will benefit from taking in fewer calories partly because.
A．humans, worms and rodents are different.
B．most people are not willing to be put on a strict diet.
C．the effect is not known.
D．genetic changes in tissues can not be performed on humans. 请帮忙给出正确答案和分析，谢谢！