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': 'RD k diagnosed by: \nSelect and explain. \nA. +90 D, B. Hurby lens, C. 3 mirror contact lens, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. All', 'role': 'assistant'}]