Statement $(A)$ $Mg$ can reduce $Al_2O_3$ above $1350^{\circ} C$.
Statement $(B)$ $Al$ can reduce $MgO$ below $1350^{\circ} C$.
The correct answer is

Statement $I :$ Leaching of gold with cyanide ion in absence of air $/$ $O_2$ leads to cyano complex of $Au(III)$.
Statement $II :$ Zinc is oxidized during the displacement reaction carried out for gold extraction.
In the light of the above statements,choose the correct answer from the options given below.

The function of fluorspar in the electrolytic reduction of alumina dissolved in fused cryolite $(Na_3AlF_6)$ is

In the $Hall-Heroult$ process,a mixture of $......$ is used as an electrolyte.

The electrolytic reduction of alumina to aluminum is made possible by the Hall-$H$éroult process in the presence of:

Gold is extracted by a hydrometallurgical process based on its property: