Explanation

(d)
Solubility of $CaF_{2} = \ 2 \times 10^{- 4}$ mol/L
Each mole of $CaF_{2}$ dissolving in $H_{2}O\$gives one mole of$\ Ca^{2 +}\$and two moles$\$of$\ F^{-}$ions.
$CaF_{2} \rightleftharpoons \ \ \ \ \ \ \ {Ca}^{2 +}\ \ \ \ \ \ \ \ + \ \ \ \ \ \ \ \ 2F^{-}$
$2 \times 10^{- 4}\ M$ $2 \times 2 \times 10^{- 4}M$
$K_{sp} = \left\lbrack {Ca}^{2 +} \right\rbrack\left\lbrack F^{-} \right\rbrack^{2}$
$= \left\lbrack 2 \times 10^{- 4} \right\rbrack\left\lbrack 2 \times 2 \times 10^{- 4} \right\rbrack^{2}$
$K_{sp} = 3.2 \times 10^{11}$