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': 'Most common complication of mastectomy is: \nSelect and explain. \nA. Seroma, B. Hemorrhage, C. Lympnedema, D. Infection', 'role': 'user'}, {'content': "Answer: A \nExplanation: Seromas beneath the skin flaps or in the axilla represent the most frequent complication of mastectomy and axillary lymph node dissection, repoedly occurring in as many as 30% of cases. Ref: Schwaz's principle of surgery 9th edition, chapter 17.", 'role': 'assistant'}]