Which of the following precipitates dissolve readily in cold dilute (about 2 M) aqueous ammonia?

Both $\mathrm{AgCl}$ and $\mathrm{Ag}{}_3\mathrm{PO}{}_4$ dissolve by forming $[\mathrm{Ag}(\mathrm{NH}{}_3){}_2]{}^{+}$ because their $K_{sp}$ values are not too small, with $K_{sp}{K}_f$ large enough. $\mathrm{AgBr}$ dissolves only in concentrated ammonia and $\mathrm{AgI}$ is practically insoluble because of its very small $K_{sp}$.