A $2.00\mathrm{kg}$ sample of bauxite contains $51.0\%$ $\mathrm{Al}{}_2\mathrm{O}{}_3$ (the rest is inert to the reagents). It is digested with excess $\mathrm{NaOH}$ by $\mathrm{Al}{}_2\mathrm{O}{}_3+2\mathrm{NaOH}+3\mathrm{H}{}_2\mathrm{O}\to 2\mathrm{Na}[\mathrm{Al}(\mathrm{OH}){}_4]$ and the aluminate is completely converted to $\mathrm{Al}(\mathrm{OH}){}_3$. Taking Al = 27, O = 16, H = 1, Na = 23, the minimum mass of $\mathrm{NaOH}$ consumed and the mass of $\mathrm{Al}(\mathrm{OH}){}_3$ obtained are respectively

1. A$800\mathrm{g}$ and $1560\mathrm{g}$
2. B$400\mathrm{g}$ and $1560\mathrm{g}$
3. C$800\mathrm{g}$ and $780\mathrm{g}$
4. D$1600\mathrm{g}$ and $1560\mathrm{g}$