This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Acquired Cataract, Subject name: Ophthalmology
[{'content': "A 10-year-old child with Fanconi's syndrome. \nSelect and explain. \nA. Vogts striae, B. Fleischer ring, C. KF ring, D. Stocker line", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) KF ring.', 'role': 'assistant'}]