The following concern AgCl ($K_{sp}=1.8\times 10^{-10}$) and $[\mathrm{Ag}(\mathrm{NH}{}_3){}_2]{}^{+}$ ($K_f=1.6\times 10^7$). Take the solubility in $0.10\mathrm{M}$ $\mathrm{NH}{}_3$ as $4.8\times 10^{-3}\mathrm{M}$ and in water as $1.3\times 10^{-5}\mathrm{M}$. Which statements are correct?

1. AThe solubility in $0.10\mathrm{M}$ $\mathrm{NH}{}_3$ is more than 300 times that in water.
2. BIn the saturated ammoniacal solution, $[\mathrm{Ag}{}^{+}]$ is about $4\times 10^{-8}\mathrm{M}$, far below its value in water.
3. CIn the saturated ammoniacal solution, $[\mathrm{Ag}{}^{+}]$ exceeds $10^{-6}\mathrm{M}$.
4. DAdding dilute $\mathrm{HNO}{}_3$ to the clear ammoniacal solution can re-precipitate AgCl.