Which of the following alloys contains $Ni$ metal?

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:

In the electrolysis of $Al_2O_3$ by the Hall-Heroult process,which of the following statements is correct?

Identify the correct statement from the following:

Among statements $(a)-(d),$ the correct ones are
$(a)$ Limestone is decomposed to $CaO$ during the extraction of iron from its oxides.
$(b)$ In the extraction of silver,silver is extracted as an anionic complex.
$(c)$ Nickel is purified by Mond's process.
$(d)$ $Zr$ and $Ti$ are purified by Van Arkel method.

Which of the following is a ferrous alloy?