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': 'Stage III lymphoma in Ann Arbour classification of lymphoma is: \nSelect and explain. \nA. Involvement of lymph node regions or lymphoid structures on both sides of the diaphragm, B. Involvement of two or more lymph node regions on the same side of the diaphragm, C. Diffuse involvement of extralymphatic lymph nodes, D. Involvement of one lymph node or a single region', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]