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
Role of 2,3 DPG in haemoglobin is 
Select and explain. 
A. Unloading oxygen to tissue, B. Increased affinity for oxygen, C. Buffering capacity, D. Osmotic fragility
A: Unloading oxygen to tissue
Answer: A: Unloading oxygen to tissue 
Explanation: None