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: Anatomy
[{'content': 'The subarachnoid space ends at: \nSelect and explain. \nA. L1, B. L2, C. L5, D. S2', 'role': 'user'}, {'content': 'Answer: A \nExplanation: D i.e. S2', 'role': 'assistant'}]