At $1500\mathrm{K}$, standard Gibbs energies of oxide formation per mole of $\mathrm{O}{}_2$ are: $2\mathrm{C}+\mathrm{O}{}_2\to 2\mathrm{CO}$ $-440\mathrm{kJ}$; $2\mathrm{Fe}+\mathrm{O}{}_2\to 2\mathrm{FeO}$ $-380\mathrm{kJ}$; $2\mathrm{Zn}+\mathrm{O}{}_2\to 2\mathrm{ZnO}$ $-300\mathrm{kJ}$; $\frac{4}{3}\mathrm{Al}+\mathrm{O}{}_2\to \frac{2}{3}\mathrm{Al}{}_2\mathrm{O}{}_3$ $-820\mathrm{kJ}$; $2\mathrm{Mg}+\mathrm{O}{}_2\to 2\mathrm{MgO}$ $-780\mathrm{kJ}$. Select the reductions that are thermodynamically feasible at $1500\mathrm{K}$ on this basis.

1. Areduction of $\mathrm{Al}{}_2\mathrm{O}{}_3$ by magnesium, giving Al and MgO
2. Breduction of $\mathrm{FeO}$ by carbon, giving Fe and CO
3. Creduction of $\mathrm{Al}{}_2\mathrm{O}{}_3$ by carbon, giving Al and CO
4. Dreduction of $\mathrm{ZnO}$ by aluminium, giving Zn and $\mathrm{Al}{}_2\mathrm{O}{}_3$