问题详情

According to Ames, which of the following can be inferred about man-made carcinogens？
A．They are no more harmful to people than a peanut-butter sandwich.
B．They are more harmful to people than a peanut-butter sandwich.
C．They are as harmful as a peanut-butter sandwich to people.
D．No definite conclusions have been made about them.请帮忙给出正确答案和分析，谢谢！