${\text{Al}}_2{\text{O}}_3$ is reduced by electrolysis. If $4.0\times 10^4\text{amperes}$ of current is passed through molten ${\text{Al}}_2{\text{O}}_3$ for $6\text{hours}$, what mass of aluminium is produced? (At. mass of $\text{Al}=27{\text{g mol}}^{-1}$)

1. A
   $8.1\times 10^4\text{g}$
2. B
   $2.4\times 10^5\text{g}$
3. C
   $1.3\times 10^4\text{g}$
4. D
   $9.0\times 10^3\text{g}$