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

The first molecule is an alkyl halide because it contains a halogen atom bound to an sp³ hybridised carbon atom, which is further bound to other alkyl groups.

The second molecule is an allyl halide which are compounds where the halogen atom is attached to a carbon atom is bonded to an sp³ hybridised carbon atom which is attached to a carbon-carbon double bond.

The third molecule is an aryl halide which is a compound where the halogen atom is attached to an aromatic ring carbon atom which is sp² hybridised.

The fourth molecule is a vinyl halide in which the halogen atom is bound to an sp² hybridised carbon atom in a carbon-carbon double bond.