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': 'In which of the following condition, constantly changing refractive error is seen: \nSelect and explain. \nA. Trauma cataract, B. Morgagnian cataract, C. Incipient cataract, D. Diabetic cataract', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In incipient cataract the refraction changes with considerable rapidity and should be corrected at frequent interval.', 'role': 'assistant'}]