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
Several segments of the polypeptide chain of integral membrane proteins usually span the lipid bilayer. These segments frequently (NOT RELATED) 
Select and explain. 
A. Adopt an a-helical configuration, B. Contain many hydrophilic amino acids, C. Form covalent bonds with cholesterol, D. Contain unusually strong peptide bonds
A: Adopt an a-helical configuration
Answer: A: Adopt an a-helical configuration 
Explanation: .