对于近似数1.00亿，下列说法正确的[ ]

A．有3个有效数字，精确到百分位

B．有3个有效数字，精确到百万位

C．有1个有效数字，精确到百分位

D．有1个有效数字，精确到百万位

—Do you think it wise for Chinese mothers to try to do everything for their children?

—No, that's _____ they are mistaken.[ ]

A. where

B. when     

C. in which  

D. what