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: Medicine
[{'content': 'Normal CSF pressure is - \nSelect and explain. \nA. 110-180 mm CSF, B. 180-300 mm, C. 200-400mm, D. 5-10 mm', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]