Concentration of the $Ag^{+}$ ions in a saturated solution of $Ag_2C_2O_4$ is $2.2x10^{-4}\; mol L^{-1}$ Solubility product of $Ag_2C_2O_4$, is:

Question

$\begin{array}{1 1} (1) 2.42 \times 10^{-8} \\ (2) 2.66 \times 10^{-12} \\ (3) 4.5 \times 10^{-13} \\ (4)3.3 \times 10^{-12}\end{array}$