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
[{'content': 'The teiary structure of protein is determined by \nSelect and explain. \nA. X-ray Crystallography, B. Spectrophotometry, C. Electrophoresis, D. Chromatography', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Three-Dimensional Structure is determined by X-ray Crystallography or by NMR SpectroscopyRef: Harper&;s Biochemistry; 30th edition; Chapter 5; Proteins: Higher Orders of Structure', 'role': 'assistant'}]