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: Unknown
[{'content': 'Earliest sign in X-ray in TB spine- \nSelect and explain. \nA. Paravertebral shadow, B. Narrowing of disc space, C. Gibbus, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans- B Narrowing of disc space First clinical sign of TB Spine = Paraspinal muscle spasm First clinical sign of Pott paraplegia = Ankle Clonus > Extensor Plantar > Spasticity First X-ray Sign of Pott spine = Reduction of disc space End result of Pott spine = bony ankylosis Loss of Spinal curvature is a non specific X-ray finding which can happen even after prolonged sitting.', 'role': 'assistant'}]