This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immune system, Subject name: Medicine
All of the following are asociated with secondary Sjogren's syndrome EXCEPT 
Select and explain. 
A. Rheumatoid ahritis, B. Primary biliary cirrhosis, C. Pheochromocytoma, D. Systemic lupus erythematosus
C: Pheochromocytoma
Answer: C: Pheochromocytoma 
Explanation: Ref - researchgate.net