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: Orthopaedics
[{'content': 'After L4- S1 the next commonest site of intervertebral disc prolapse is - \nSelect and explain. \nA. C6 - C7, B. T12 - LI, C. L1- L2, D. L2 - L3', 'role': 'user'}, {'content': 'Answer: A \nExplanation: L5 and L4 - L5 level →\xa080%.\nC5 - C6 and C6–7 level → 19-20%.', 'role': 'assistant'}]