This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lens, Subject name: Ophthalmology
[{'content': 'Equatorial diameter of the lens is- \nSelect and explain. \nA. 7mm, B. 8mm, C. 9mm, D. 10mm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Equatorial diameter of lens is 10mm. Ref: Foster 2nd/e p.1912.', 'role': 'assistant'}]