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: Medicine
[{'content': 'Most common symptom in Pulmonary embolism is - \nSelect and explain. \nA. Chest pain, B. Dyspnea, C. Palpitations, D. Calf pain', 'role': 'user'}, {'content': "Answer: B \nExplanation: Dyspnea is the most common symptom of PE,and tachypnea is the most common sign.Dyspnea,syncope,hypotension,or cyanosis indicates a massive pulmonary embolism;whereas pleuritic pain,cough,or hemoptysis often suggests a small embolism situated distally near the pleura. Reference:Harrison' s medicine-18th edition,page no:2172.", 'role': 'assistant'}]