Assertion (A): Olefinic monomers undergo addition polymerization. 
Reason(R): Polymerization of vinyl chloride is initiated by peroxides/ persulphates .
 

In addition polymerization, the molecules of the same monomer or different monomers add together on a large scale to form polymer. The monomers used are unsaturated compounds, e.g., alkenes, alkadienes and their derivatives. This mode of polymerization leading to an increase in chain length or chain growth can takes place through the formation of either free radicals or ionic species.