If $H_{2}S$ is passed into the above mixture in the presence of HCl, which ion will be precipitated first?

The correct option is C SnS

Compound with higher solubility constant will be more soluble.

Here, among given compounds $SnS(K_{sp}=8\times {10}^{-29})$ has the least solubility constant. So its solubility will be minimum and it will precipitate first.