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: Ophthalmology
[{'content': 'Cataract is caused by all except – \nSelect and explain. \nA. Ultraviolet radiation, B. MRI, C. Infrared radiation, D. Microwave radiation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Radiation cataract is caused by ionizing & non-ionizing radiations e.g. UV rays, neutron, radium, ultrasonics; but MRI has no radiation exposure.', 'role': 'assistant'}]