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': "All are seen in stage III trachoma except – \nSelect and explain. \nA. Tarsal epitheliofibrosis, B. Trachomatous pannus, C. Herbert's pits, D. Disappearance of Bowman's membrane", 'role': 'user'}, {'content': "Answer: B \nExplanation: McCallan's classification-McCallan in 1908 divided the clinical course of trachoma into 4 stages", 'role': 'assistant'}]