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
Protein purification and separation can be done by all except 
Select and explain. 
A. Chromatography, B. Centrifugation, C. Electrophoresis, D. None
D: None
Answer: D: None 
Explanation: Techniques for protein separation:ChromatographyColumn ChromatographyPaition ChromatographySize Exclusion ChromatographyAdsorption ChromatographyIon Exchange ChromatographyAffinity ChromatographyHigh-Pressure Liquid ChromatographyGas ChromatographyPAGEIEFSalting out with ammonia sulfateRef: Harper 28th Ed. Page-21, Harper 27th Ed. Page: 21