Among the following, the reaction that proceeds through an electrophilic substitution, is :

The correct option is C
The reaction given in option (b) is chlorination of benzene in presence of lewis acid. Here, the $C{l}^{+}$ ion is formed which act as electrophile. This reaction is an example of aromatic electrophilic substitution.

Reaction (a) and (d) are nucleophilic substitution.
Reaction (c) is free radical addition reaction.
Hence, option (b) is correct.