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': 'Topical sodium cromoglycate is used in the treatment of – \nSelect and explain. \nA. Phlyctenular conjunctivitis, B. Vernal catarrh, C. Subconjunctival haemorrhage, D. Trachoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Mast cell stabilizers such as sodium chromoglycate drops are quite effective in controlling vernal keratoconjunctivitis.', 'role': 'assistant'}]