This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Breast, Subject name: Surgery
[{'content': 'Retromammary abcess arises from: \nSelect and explain. \nA. Tuberculous rib, B. Infected haematoma, C. Chronic empyema, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans: d (All of the above)Ref: Still searching', 'role': 'assistant'}]