This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: HAEM synth and porphyrias, Subject name: Biochemistry
All of the following will cause a shift to the right of the oxygen-hemoglobin dissociation curve, EXCEPT 
Select and explain. 
A. Hypoxia, B. 2,3 DPG, C. Increase in pH, D. Increase in temperature
C: Increase in pH
Answer: C: Increase in pH 
Explanation: In oxygen dissociation curve (ODC) of Hb, paial pressure of oxygen is plotted on the X-axis and percentage of hemoglobin saturated with oxygen is plotted on the Y-axis. We get a sigmoidal curve for hemoglobin. Shift of oxygen dissociation curve to right refers to the increased unloading of oxygen. Imagine a person doing exercise in a warm room. Raised CO2, temperature, 2,3-DPG and decreased pH causes shift of ODC to right.