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: Anatomy
In rheumatoid ahritis which pa of spinal column is most commonly involved ? 
Select and explain. 
A. Cervical veebra, B. Dorsal veebra, C. Lumbar veebra, D. Sacral veebra
A: Cervical veebra
Answer: A: Cervical veebra 
Explanation: Upper cervical spine is involved in RA Refer Harrison 17the p 2083/maheswari 9th ed