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
Hemoglobin binds/transpos all except ? 
Select and explain. 
A. CO, B. O2, C. SO2, D. CO2
C: SO2
Answer: C: SO2 
Explanation: Ans. is 'c' i.e., SO2