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
[{'content': 'Which is the only amino acid with good buffering capacity at physiological pH? \nSelect and explain. \nA. Arginine, B. Glutamic acid, C. Histidine, D. Valine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Histidine plays a key role in making\xa0hemoglobin an excellent buffer in red blood cells.', 'role': 'assistant'}]