The fibre obtained by the condensation of hexamethylen, diamine and adipic acid is
A. `barO OC - (CH_(2))_(4) - CObarO overset(+)(N) H_(3) - (CH_(2))_(6) - overset(+)(N)H_(3)`
B. `-overset(O)overset(||)(C) - (CH_(2))_(4) - overset(O)overset(||)(C)- NH - (CH_(2))_(6) - NH-`
C. `H_(3) overset(+)(N) - (CH_(2))_(5) - overset(+)(N)H_(3) barO O C - (CH_(2))_(4) - CO barO`
D. `H_(2)N - (CH_(2))_(6) - overset(+)(N) H_(3) barO - overset(||)(O) - (CH_(2))_(4) - overset(O)overset(||)(C)- OH`
