This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
[{'content': 'Several segments of the polypeptide chain of integral membrane proteins usually span the lipid bilayer. These segments frequently (NOT RELATED) \nSelect and explain. \nA. Adopt an a-helical configuration, B. Contain many hydrophilic amino acids, C. Form covalent bonds with cholesterol, D. Contain unusually strong peptide bonds', 'role': 'user'}, {'content': 'Answer: A \nExplanation: .', 'role': 'assistant'}]