Which of the following will form a precipitate with excess KI?

In excess of $\mathrm{KI},{\mathrm{Hg}}^{2+}\mathrm{and}{\mathrm{Bi}}^{3+}$will form soluble complex and ${\mathrm{NH}}_4^{+}$ will form soluble ammonium iodide, ${\mathrm{NH}}_4^{ }\mathrm{I}.$ Only ${\mathrm{Ag}}^{+}$ will form a yellow precipitate of AgI which is insoluble in excess of KI