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': 'Regarding spring catarrh, all of the following are true, except: \nSelect and explain. \nA. Cobblestone appearance of conjunctiva, B. Common in spring months, C. Limbus conjunctival thickening, D. Sodium cromoglycate is a form of therapy', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Limbus conjunctival thickening', 'role': 'assistant'}]