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': 'True about cornea: \nSelect and explain. \nA. Power is 43 D, B. Majority of refraction occur at air-tear interface, C. With the rule astigmatism is present because veical meridian more sleep than horizontal meridian, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. All A, B and C', 'role': 'assistant'}]