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': "Prophylactic cranial irradiation not indicated in treatment of - \nSelect and explain. \nA. Small cell Ca of lung, B. ALL, C. Hodgkin's lymphoma, D. NHL", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]