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 of the following aminoacids have maximum buffering capacity at PH 7? \nSelect and explain. \nA. Lysine, B. Arginine, C. Histidine, D. Glycine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: pKa of histidine is 6.5 - 7.4. It allows for maximum buffering capacity at neutral pH.', 'role': 'assistant'}]