This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Conjunctiva, Subject name: Ophthalmology
[{'content': 'Vision 2020: Right to sight by WHO targets all except: \nSelect and explain. \nA. Cataract, B. Trachoma, C. Epidemic keratoconjunctivitis, D. Oncocerciasis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]