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. γ-rays, C. α-particles, D. β-particles', 'role': 'user'}, {'content': 'Answer: A \nExplanation: X-rays - Linear accelerator.\nγ-rays - emitted by radioactive materials.', 'role': 'assistant'}]