This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
[{'content': '"Fleischer ring" is a distinct feature of NOT RELATED-PATHOLOGY \nSelect and explain. \nA. Keratoconus, B. Pterygium, C. Congenital ocular melanosis, D. Congenital epithelial Melanosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: .', 'role': 'assistant'}]