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': 'Left loin nephrectomy, Str. not cut is - \nSelect and explain. \nA. Trapezius, B. Seratus inf. post, C. Lat. dorsi, D. Internal oblique', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]