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': 'In microcornea, diameter of cornea is less than: \nSelect and explain. \nA. 9 mm, B. 10 mm, C. 11 mm, D. 8 mm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. 10 mm', 'role': 'assistant'}]