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: Physiology
[{'content': 'Role of 2,3 DPG in haemoglobin is \nSelect and explain. \nA. Unloading oxygen to tissue, B. Increased affinity for oxygen, C. Buffering capacity, D. Osmotic fragility', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]