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': 'Immune ring in the cornea is a feature of: \nSelect and explain. \nA. Bacterial corneal ulcer, B. Fungal corneal ulcer, C. Ring ulcer of the cornea, D. Disciform keratitis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Fungal corneal ulcer', 'role': 'assistant'}]