This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
All the following are hydrophilic amino acids Except 
Select and explain. 
A. Cysteine, B. Proline, C. Glycine, D. Serine
B: Proline
Answer: B: Proline 
Explanation: Hydrophilic & Hydrophobic Amino AcidsHydrophilicHydrophobicArginineAlanineAsparagineIsoleucineAspaic acidLeucineCysteineMethionineGlutamic acidPhenylalanineGlutamineProlineGlycineTryptophanHistidineTyrosineLysineValineSerineThreonineRef: Harper&;s Biochemistry; 30th edition; Chapter 3; Amino Acids & Peptides