This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vascular surgery, Subject name: Surgery
[{'content': 'Most common site of lymphangiosarcoma is \nSelect and explain. \nA. Liver, B. Spleen, C. Retroperitoneum, D. Post mastectomy arm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Most common site of lymphangiosarcoma is arm following mastectomy, Occurs commonly after radical lymph nodes dissection- stewa treves syndrome Reference- SRB - 5th edition, sarcoma, page 311.', 'role': 'assistant'}]