Polymerization is where single molecules react with themselves and form a chain, a branch or a combination of both. There are repeated unites within the resulted polymer. This is the reactant (single molecule or monomer). As a result, the number of polymer is always less than the number of the monomer. Therefore, 1 mole of monomer, under complete polymerization, always forms less than 1 mole of polymer. Answer is b and c.
