At 1200 K, per mole of $\mathrm{O}{}_2$, $\Delta G^{\circ }$ values (in $\mathrm{kJ}$) are $-880$ for $\frac{4}{3}\mathrm{Al}+\mathrm{O}{}_2\to \frac{2}{3}\mathrm{Al}{}_2\mathrm{O}{}_3$ and $-640$ for $\frac{4}{3}\mathrm{Cr}+\mathrm{O}{}_2\to \frac{2}{3}\mathrm{Cr}{}_2\mathrm{O}{}_3$. If aluminothermy is feasible at 1200 K, the mass of $90\%$ pure aluminium needed to reduce $152\mathrm{kg}$ of $\mathrm{Cr}{}_2\mathrm{O}{}_3$ (Cr 52, O 16, Al 27) completely is

1. A$90.0\mathrm{kg}$
2. B$60.0\mathrm{kg}$
3. C$54.0\mathrm{kg}$
4. Dnot feasible, since $\mathrm{Cr}{}_2\mathrm{O}{}_3$ has the higher $\Delta G^{\circ }$