Given $E^{\circ }$ values: $\mathrm{Fe}{}^{3+}/\mathrm{Fe}{}^{2+}=0.77$, $\mathrm{Cu}{}^{2+}/\mathrm{Cu}=0.34$, $\mathrm{Ag}{}^{+}/\mathrm{Ag}=0.80$, $\mathrm{Zn}{}^{2+}/\mathrm{Zn}=-0.76\mathrm{V}$. Which pair cannot coexist in an aqueous solution under standard conditions?

1. A$\mathrm{Fe}{}^{3+}$ and $\mathrm{Cu}(\mathrm{s})$
2. B$\mathrm{Fe}{}^{2+}$ and $\mathrm{Cu}{}^{2+}$
3. C$\mathrm{Zn}{}^{2+}$ and $\mathrm{Cu}{}^{2+}$
4. D$\mathrm{Ag}{}^{+}$ and $\mathrm{Fe}{}^{3+}$