Concentration of the $Ag^+$ ions in a saturated solution of $Ag_2C_2O_4$ is $2.2 \times 10^{-4} \; mol\; L^{-1}$. Solubility product of $Ag_2C_2 O_4$ is :

Question

( A ) $2.66 \times 10^{-12}$
( B ) $5.3 \times 10^{-12}$
( C ) $2.42 \times 10^{-8}$
( D ) $4.5 \times 10^{-11}$