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: Anatomy
[{'content': 'Which of these muscles is not cut in postero lateral thoractomy : \nSelect and explain. \nA. Serratus anterior, B. Pectoralis major, C. Latissimus dorsi, D. Intercostals', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B. i.e. Pectoralis major', 'role': 'assistant'}]