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 and α-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.