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
Retromammary abscess arises from- 
Select and explain. 
A. Tuberculous rib, B. Infected hematoma, C. Chronic empyema, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: • It may an extension of Breast abscess, Empyema thoracis, Osteomyelitis of the ribs.
• No need to drain retromammary abscess, only conservative treatment.