This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
In which type of chromatography, the proteins are bound to another substance: 
Select and explain. 
A. Hydrophobic chromatography, B. Affinity chromatography, C. Paper chromatography, D. Gel chromatography
B: Affinity chromatography
Answer: B: Affinity chromatography 
Explanation: B i.e. Affinity chromatography