This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea, Subject name: Ophthalmology
[{'content': 'K F Ring is seen in- \nSelect and explain. \nA. Chalcosis, B. Sarcoidosis, C. Tuberous Sclerosis, D. VKH Syndrome', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Chalcosis * Kayser-Fleischer (KF) ring - Copper deposition in Chalcosis or Wilson's disease* Fleischer ring - Deposition of iron and is a sign of keratoconus", 'role': 'assistant'}]