Options
A) A=1° structure, B = 2° structure, C = 3° structure, D = 4° structure
B) A=4° structure, B = 2° structure, C = 3° structure, D = 1° structure
C) A=1° structure, B = 4° sstructure, C = 3° structure, D = 2° structure
D) A=4° structure, B = 3° structure, C = 2° structure, D = 1° structure