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. Ventilation perfusion mismatch, C. Bronchial asthma, D. Inapporpriate gas exchange', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]