The diagram illustrates apparatus that may be used to extract aluminium from its ore. What are $J$, $K$ and $L$?
- A$J$: negative electrode; $K$: aluminium oxide $+\,$ cryolite; $L$: aluminium
- B$J$: negative electrode; $K$: cryolite; $L$: aluminium oxide
- C$J$: positive electrode; $K$: aluminium oxide; $L$: cryolite
- D$J$: positive electrode; $K$: aluminium oxide $+\,$ cryolite; $L$: aluminium