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
Proteins are separated on the basis of charge in ? 
Select and explain. 
A. SDS-PAGE, B. Ultracentrifugation, C. Affinity chromatography, D. HPLC
D: HPLC
Answer: D: HPLC 
Explanation: Ans. is 'd' i.e., HPLC