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: Forensic Medicine
[{'content': 'Commonest cause of pulmonary embolism is: CMC (Vellore) 09 \nSelect and explain. \nA. Fat, B. Amniotic fluid, C. Thrombus, D. Air', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. Thrombus', 'role': 'assistant'}]