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
Stage III lymphoma in Ann Arbour classification of lymphoma is: 
Select and explain. 
A. 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
A: Involvement of lymph node regions or lymphoid structures on both sides of the diaphragm
Answer: A: Involvement of lymph node regions or lymphoid structures on both sides of the diaphragm 
Explanation: None