A water sample has ppm level concentntion of following anions
`F^(-)=10,SO_(4)^(2-)=100,NO_(3)^(-)=50`
the anion/anions that make/makes the water sample unsuitable for drinking is/are :

Options

A. only `NO_(3)^(-)`
B. both `SO_(4)^(2-) and NO_(3)^(-)`
C. only `F^(-)`
D. only `SO_(4)^(2-)`

Answer

C

Explanation

Above 2 ppm concentration of `F^(-)` in drinking water cause brown mottling of teeth.