This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nuclear medicine, Subject name: Radiology
[{'content': 'Radioisotopes emit all the following except? \nSelect and explain. \nA. Alpha Rays, B. Beta Rays, C. Gamma Rays, D. X-rays', 'role': 'user'}, {'content': 'Answer: D \nExplanation: X rays are aificially produced in the Xray tube or by using LINAC(Linear Accelerator) Radioisotopes emit either Alpha Rays,Beta Rays and Gamma Rays', 'role': 'assistant'}]