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
[{'content': 'High Oxygen tension in alveoli is due to: \nSelect and explain. \nA. Right to left shunt, B. Right to left shunt, C. Bronchial Asthma, D. Inappropriate gas exchange', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Ventilation - Perfusion mismatch', 'role': 'assistant'}]