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': 'Linear accelerator produces: \nSelect and explain. \nA. X-rays, B. Gamma rays, C. Beta rays, D. Neutrons', 'role': 'user'}, {'content': 'Answer: A \nExplanation: X-rays', 'role': 'assistant'}]