This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Anatomy
[{'content': 'The most commonest cause of acute cor pulmonale is \nSelect and explain. \nA. Pneumonia, B. Pulmonary thromboembolism, C. COPD, D. primary spontaneous pneumothorax', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref Harrison 19 th ed pg 1454 ,1505 The most commonest cause of acute cor pulmonale is pulmonary thromboembolism. The most common cause of chronic cor pulmonale is COPD.', 'role': 'assistant'}]