(i) → (b) (ii) → (a) (iii) → (d) (iv) → (c)

The first reaction is a Wurtz-Fittig reaction where an alkyl halide and an aryl halide react in the presence of Na metal in dry ether to form alkylarene.

The second reaction is the Fittig reaction where a coupling reaction between two arylhalides takes place in the presence of Na metal in dry ether, forming diaryl compounds.

The third reaction is Sandmeyer reaction where aryl halides are prepared from primary amines by conversion into diazonium salt and treatment with cuprous bromide.

The fourth reaction is the Finkelstein reaction where alkyl iodides are prepared by reaction of alkyl chlorides or bromides with NaI in dry acetone.