A water sample has ppm level concentration 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 :

Question

$\begin{array}{1 1} \text{(1) only} F^− \\ (2) only\; SO_4^{2−} \\ (3) only\; NO_3^{−} \\ (4) both\;SO_4^{2-} \;and \;NO_3^{-} \end{array}$