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: Unknown
[{'content': '35 year old male with history of 4 weeks of immobilization for fracture femur developed sudden onset of chest pain and hemoptysis.  ECG shows s1 Q3 T3 pattern. Diagnosis? \nSelect and explain. \nA. Acute myocardial infarct, B. COPD, C. Pulmonary embolism, D. Cor pulmonale', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ref. Grainger and Allison's Diagnostic Radiology. Page. 50\n\xa0\nPulmonary embolism (PE) usually arises from a venous thrombosis in the pelvis or legs\n\nRisk factors include any cause of immobility or hyper coagulability .\nClinical features include :pleuritic chest pain ,sudden onset of breathlessness (most common),hemoptysis ,dizziness ,syncope .\nECG findings include sinus tachycardia (most common ) , S1Q3T3 (Most characteristic)", 'role': 'assistant'}]