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: Radiology
[{'content': 'Hodgkin lymphoma is treated by: March 2013 (b, d) \nSelect and explain. \nA. 20-30 Gy, B. 30-40 Gy, C. 40-50 Gy, D. 50-60 Gy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A i.e. 20-30 Gy', 'role': 'assistant'}]