• In case of (iii) Iodobenzene different reagents as KI used to obtain the product because it cannot be formed in presence of Cu(I) ( Iodine being less reactive than other halogens)

• And for (iv) Fluoro-benzene it cannot be formed by this reaction due to the high reactivity of Fluorine the reaction b/w F and benzene and rigorous and highly explosive.

The other 2 options (i) Chlorobenzene (ii) Bromobenzene can be formed by this reaction.