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

Gold is extracted by the formation of a soluble cyanide complex. What is the formula of this cyanide complex?

Aluminium is extracted from alumina $Al_2O_3$ by electrolysis of a molten mixture of

The modern method of steel manufacturing is

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R).$
Assertion $(A):$ Aluminium is extracted from bauxite by the electrolysis of a molten mixture of $Al_2O_3$ with cryolite.
Reason $(R):$ The oxidation state of $Al$ in cryolite is $+3$.
In the light of the above statements,choose the most appropriate answer from the options given below:

Flux is used to remove