Data in kJ/mol: for Cu, enthalpy of atomisation 340, ${\Delta }_i{H}_1+{\Delta }_i{H}_2=2700$, hydration enthalpy of $\mathrm{Cu}{}^{2+}$ $-2120$; for Zn, enthalpy of atomisation 130, ${\Delta }_i{H}_1+{\Delta }_i{H}_2=2640$, hydration enthalpy of $\mathrm{Zn}{}^{2+}$ $-2050$. Which conclusion about $E^{\circ }(\mathrm{M}{}^{2+}/\mathrm{M})$ is correct?

1. AThe net energy for $\mathrm{M}(\mathrm{s})\to \mathrm{M}{}^{2+}(\mathrm{aq})$ is $920$ for Cu and $720$ for Zn, so Cu is far less able to form $\mathrm{M}{}^{2+}(\mathrm{aq})$ and its $E^{\circ }$ is more positive
2. BThe net energies are equal, so both have the same $E^{\circ }$ and any difference is due to entropy
3. CThe net energy is $720$ for Cu and $920$ for Zn, so Cu has the more negative $E^{\circ }$
4. DHydration enthalpy alone decides $E^{\circ }$, so Zn with the less negative value is more positive