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
The factor responsible for the left shift of Hb-02 dissociation curve is: 
Select and explain. 
A. Increase in 2,3 DPG in RBC, B. Fall in temperature, C. Fall in pH, D. Increase level of CO2 in blood
B: Fall in temperature
Answer: B: Fall in temperature 
Explanation: B i.e. Fall in Temperature