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': 'Normal values of Schirmer-I test are: \nSelect and explain. \nA. 5 mm, B. 10 mm, C. 15 mm, D. 15 mm or above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. 15 mm or above', 'role': 'assistant'}]