Need help on to answering this with explanation please so I can then understand the topic, thank you

1. Show the repeating unit which would be obtained in the polymerization of: H (a) H.C-C-CH-CH , H (b) CH-C-CN CH, NCO + HN-CH-CH-NH, (c) NCO (d) H- CC-H -CH. and O=C o (e) HOOC HOCH,CH,OH and H COOH