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': 'Anterior posterior diameter of Eye ball is \nSelect and explain. \nA. 23 mm, B. 23.5 mm, C. 22 mm, D. 24 mm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Anterior posterior diameter of Eye ball is 24 mm.', 'role': 'assistant'}]