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': 'Structure preserved in Modified radical mastectomy is: September 2006, 2009 \nSelect and explain. \nA. Axillary vein, B. Pectoralis major muscle, C. Nerves to serratus anterior, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D: All of the above', 'role': 'assistant'}]