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': 'Ca breast Stage T4b involves all except: \nSelect and explain. \nA. Nipple retraction, B. Skin ulcer over the swelling, C. Dermal edema, D. Satellite nodule', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]