75. The H-bonds formed in the tertiary structure of proteins can be differentiated from those formed in secondary structures.What is the major distinguishing factor? 
(A) The H-bonds in 3° structures are significantly stronger than those found in 2° structures. 
(B) The H-bonds in 3° structures are more random than those formed in 2° structures.
(C) The H-bonds in 3° structures are formed by predictable interactions among the peptide backbone α-amine andα-carboxylate groups. 
(D) The H-bonds in 3° structures are formed by interactions involving the side chain R-groups. 
(E) Both B and D are correct.