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': 'Maximum Radiation exposure occurs from: \nSelect and explain. \nA. Bone scan, B. CT scan, C. X-ray, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Radiation Exposure:\nBone scan > CT scan > X-ray (But MRI given in option, then it is the answer).', 'role': 'assistant'}]