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': 'Radiation exposure occurs in all of the following except: \nSelect and explain. \nA. CT scan, B. MRI, C. Fluoroscopy, D. Plain X-ray', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. MRI', 'role': 'assistant'}]