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': 'In fracture of femur popliteal aery is commonly damaged by \nSelect and explain. \nA. Proximal fragment, B. Distal fragment, C. Muscle haematoma, D. Tissue swelling', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Distal fragment lit fracture supracondylar femur, the distal fragmentQ is markedly displaced by gastrocnemius, thus risking to the popliteal aery.', 'role': 'assistant'}]