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: Anaesthesia
[{'content': 'Pudendal nerve block involves \nSelect and explain. \nA. Ll, L2, L3, B. L3, L4,L5, C. Sl, S2, S3, D. S2, S3, S4', 'role': 'user'}, {'content': 'Answer: D \nExplanation: S2, S3, S4', 'role': 'assistant'}]