The straight chain polymer is formed by -

hydrolysis of $\left(\mathrm{CH}_3\right)_2 \mathrm{SiCl}_2$ followed by condensation polymerization
hydrolysis of $\left(\mathrm{CH}_3\right)_3 \mathrm{SiCl}$ followed by condensation polymerization
hydrolysis of $\mathrm{CH}_3 \mathrm{SiCl}_3$ followed by condensation polymerization
hydrolysis of $\left(\mathrm{CH}_3\right)_4 \mathrm{Si}$ by addition polymerization

Asked in: NEET 2009 (Mains)