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': 'Adult size of the cornea is attained by the age of: \nSelect and explain. \nA. 2 years, B. 3 years, C. 5 years, D. 9 years', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. 2 years', 'role': 'assistant'}]