This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Classification and metabolism of amino acids, Subject name: Biochemistry
Column chromatography using phenyl Sepharose beads separates proteins based on the 
Select and explain. 
A. Affinity to ligand, B. Charge, C. Hydrophobicity, D. Stokes' radius
C: Hydrophobicity
Answer: C: Hydrophobicity 
Explanation: Hydrophobic interaction chromatography separates proteins based on their tendency to associate with a stationary phase matrix coated with hydrophobic groups(eg.phenyl Sepharose)