2. Eric uses a computer software to simulate a 20-residue peptide in different structures. Structure A is an α-helixstructure; structure B is a β-strand; structure C is a helix in the collagen structure. The length of these structuresshould be:
(A)C＞B＞A
(B) C＞A＞B
(C) B＞A＞C
(D) A＞B＞C
(E) B＞C＞A