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 64 year old hypeensive obsese female was undergoing surgery for fracture femur under general anaesthesia. Intra-operatively her end-tidal carbon dioxide decreased to 20 from 40 mm of Hg, followed by hypotension and oxygen saturation of 85%. What could be the most probable cause? \nSelect and explain. \nA. Fat embolism, B. Hypovolemia, C. Bronchospasm, D. Myocardial infarction', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Fat embolism', 'role': 'assistant'}]