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': 'In an adult, the spinal cord ends at - \nSelect and explain. \nA. T12- L1, B. L1-L2, C. L3-L4, D. S1-S2', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]