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': 'An increase in which of the following parameters will shift the O2 dissociation curve to the left: \nSelect and explain. \nA. Temperature, B. Paial pressure of CO2, C. 2,3 DPG concentration, D. Oxygen affinity of hemoglobin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Oxygen affinity of hemoglobin', 'role': 'assistant'}]