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
Ventilation perfusion ratio is: 
Select and explain. 
A. 0.5, B. 0.8, C. 1, D. 1.2
B: 0.8
Answer: B: 0.8 
Explanation: On an average, ventilation perfusion ratio is 0.8. It can be as low as 0.6 at the base of the lung and can be 2.5 times the normal value at the apex of the lung.