【单选题】

饮水加氟适用于龋病高发区和
A．水氟＜0.3ppm，氟牙症指数＜0.2

B．水氟＜0.4ppm，氟牙症指数＜0.3
C．水氟＜0.2ppm，氟牙症指数＜0.1
D．水氟＜0.4ppm，氟牙症指数＜0.2
E．水氟＜0.3ppm，氟牙症指数＜0.3