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': "Pauvel's angle is \nSelect and explain. \nA. Neck shaft angle of femur, B. The difference between neck shaft angle between two femurs of a patient, C. Formed by joining a line extended from fracture line of femur neck to an arbitrary line depicting the horizontal plane, D. None of the above", 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Formed by joining a line extended from fracture line of femur neck to an arbitrary line depicting the horizontal plane', 'role': 'assistant'}]