Which of the following sulphides has the maximum solubility product?

The more is ${\mathrm{K}}_{\mathrm{sp}}$, the higher is solubility. Also in the presence of HCl, ${\mathrm{H}}_2\mathrm{S}$ gives less $\left[{\mathrm{S}}^{2-}\right]$ which is sufficient only to cross over the ${\mathrm{K}}_{\mathrm{sp}}$ of group II sulphide