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': 'Prolapsed intervertebral Disc (PID) is most common at - \nSelect and explain. \nA. C10C11, B. C2,C3, C. L2L4, D. L5S1', 'role': 'user'}, {'content': 'Answer: D \nExplanation: L5 - SI disc space is the most commonly involved space in disc prolapse.\n\n"Lumbar intervertebral disc herniation is most common at L5 - SI and slightly less common at L4 - L5, and rare at\xa0L3 - L4 or above".\n"The disc at L5 - Si is most commonly involved, followed in order by L4 - L5 and L3 - L4".\xa0— Pocket book of orthopaedics', 'role': 'assistant'}]