Polyvinyl acetate, PVA, is a useful adhesive for gluing together articles made from wood, paper or cardboard. The monomer of PVA is ethenyl ethanoate.
PVA is formed from B by the process of addition polymerisation.
Draw a section of the PVA molecule containing at least 2 monomer molecules and identify clearly the repeating unit.
(Source: University of Cambridge international Examinations, General Certificate of Education Advanced Level, Chemistry, Paper 4 Structured Questions, May/June 2011, Q4)
Shouldn't the $\ce{C=C}$ double bond break and each of the carbon atoms involved in the double bond are attached to $\ce{CH3OCO}$. so the repeating unit is $\ce{CH3OCO}$.