Select the correct option regarding the processes used during metal extraction from their ores.

Railway wagon axles are made by heating rods of iron embedded in charcoal powder. The process is known as

Match List-$I$ with List-$II$.

List-$I$ (Industrial process)	List-$II$ (Application)
$(a)$ Haber's process	$(i)$ $HNO_{3}$ synthesis
$(b)$ Ostwald's process	$(ii)$ Aluminium extraction
$(c)$ Contact process	$(iii)$ $NH_{3}$ synthesis
$(d)$ Hall-Heroult process	$(iv)$ $H_{2}SO_{4}$ synthesis

Choose the correct answer from the options given below:

Which of the following pairs is incorrectly matched?

Stainless steel is an alloy of

In aluminium extraction by the Bayer process, alumina is extracted from bauxite by sodium hydroxide at high temperature and pressure: $Al_2O_{3(s)} + 2 OH^-_{(aq)} + 3 H_2O_{(l)} \rightarrow 2 [Al(OH)_4]^-_{(aq)}$. Solid impurities such as $Fe_2O_3$ and $SiO_2$ are removed and then $[Al(OH)_4]^-$ is reprecipitated: $2 [Al(OH)_4]^-_{(aq)} \rightarrow Al_2O_3 \cdot 3 H_2O_{(s)} + 2 OH^-_{(aq)}$. In the industrial world: