The correct options are
A Bayer’s process
B Hall’s process
The purification process of aluminium is based on the amphoteric nature of aluminium oxides. Since aluminium is found in the compounds with other elements, it needs to be reduced. The Bayer process is essentially referring to the refining of bauxite, the most important aluminium ore, to produce alumina. From here, the intermediate alumina must be smelted into metallic aluminium through the Hall-Heroult Process.