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
High Oxygen tension in alveoli is due to: 
Select and explain. 
A. Right to left shunt, B. Right to left shunt, C. Bronchial Asthma, D. Inappropriate gas exchange
B: Right to left shunt
Answer: B: Right to left shunt 
Explanation: B i.e. Ventilation - Perfusion mismatch