If pH of a saturated solution of $Ba(OH)_2$ is 12, the value of its $K_{(SP)}$ is

Question

( A ) $5.00\times10^{-7} $
( B ) $5.00\times10^-{6} $
( C ) $5.00\times10^{-7} $
( D ) $5.00\times10^{-6} $