This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: TB of the Spine, Subject name: Orthopaedics
The 1st sign of TB is: 
Select and explain. 
A. Narrowing of intervertebral space, B. Rarefaction of vertebral bodies, C. Destruction of laminae, D. Fusion of spinous processes
A: Narrowing of intervertebral space
Answer: A: Narrowing of intervertebral space 
Explanation: (a)- The earliest feature is loss of curvature due to paravertebral spasm.- The next radiological feature of spinal tuberculosis is reduction of intervertebral disk space and osteoporosis of two adjacent vertebrae sometimes with fuzziness of the endplates.