What Is the Equilibrium Constant Expression for the Dissolution of Solid

What is the equilibrium constant expression for the dissolution of solid lead oxalate,PbC₂O₄,in water?

A) $K_{s p}=\left[\mathrm{Pb}^{2+}\right]\left[\mathrm{C}_{2} \mathrm{O}_{4}^{2-}\right]$
B) K_sp = [Pb]² [C₂O₄]²
C) $K_{\mathrm{sp}}=\frac{\left[\mathrm{Pb}^{2+}\right]\left[\mathrm{C}_{2} \mathrm{O}_{4}^{2-}\right]}{\left[\mathrm{PbC}_{2} \mathrm{O}_{4}\right]}$
D) $K_{\mathrm{sp}}=\frac{\left[\mathrm{Pb}^{2+}\right]\left[\mathrm{C}^{4+}\right]^{2}\left[\mathrm{O}^{2-}\right]^{4}}{\left[\mathrm{PbC}_{2} \mathrm{O}_{4}\right]}$
E) $K_{\mathrm{sp}}=\left[\mathrm{Pb}^{2+}\right]\left[\mathrm{C}_{2}\right]\left[\mathrm{O}_{4}^{2-}\right]$