A short fragment of a biodegradable polymer chain (three units, end groups shown) is drawn. Select all correct statements.

This is a piece of nylon 2-nylon 6, an alternating copolymer of glycine and 6-aminohexanoic acid linked entirely by amide bonds (two in the fragment). Complete hydrolysis of the fragment gives glycine and 6-aminohexanoic acid, which are two different compounds, so statement C (three) is wrong. The chain has no ester.