Match List I (substances) with List II (processes) employed in the manufacture of the substances and select the correct option.

Column $${\rm I}$$ (Substances)			Column $${\rm I}$$$${\rm I}$$ (Processes)
(A)	Sulphuric acid		(i)	Haber's process
(B)	Steel		(ii)	Bessemer's process
(C)	Sodium hydroxide		(iii)	Leblanc process
(D)	Ammonia		(iv)	Contact process

Which of the following pairs has the same size?

Which of the following ions has electronic configuration [Ar]3d⁶?
(At. nos. Mn = 25, Fe = 26, Co = 27, Ni = 28)

Which of the following ions will exhibit colour in aqueous solutions?