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: Surgery
[{'content': 'A young male presented with dyspnea, bleeding and petechial hemorrhage in the chest after 2 days following fracture shaft of the femur right side. Most likely cause is - \nSelect and explain. \nA. Air embolism, B. Fat embolism, C. Pulmonary thrombo-embolism, D. Amniotic fluid embolism', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]