Take the repeat unit of nylon 6 as $-[\mathrm{NH}-(\mathrm{CH}{}_2){}_5-\mathrm{CO}]{}^{-}$ (113 g/mol) and of nylon 6,6 as $-[\mathrm{NH}-(\mathrm{CH}{}_2){}_6-\mathrm{NH}-\mathrm{CO}-(\mathrm{CH}{}_2){}_4-\mathrm{CO}]{}^{-}$ (226 g/mol). Two samples, one of each polymer, both have molar mass $22600\mathrm{g}\mathrm{mo}{\mathrm{l}}^{-1}$. The ratio of degree of polymerisation (number of repeat units), nylon 6 : nylon 6,6, is

1. A2 : 1
2. B1 : 2
3. C1 : 1
4. D4 : 1