This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mycobacterial Infections, Subject name: Dental
Main cytokine in ENL reaction: 
Select and explain. 
A. TNF-a, B. IL-2, C. IFN, D. IL-12
A: TNF-a
Answer: A: TNF-a 
Explanation: Main cytokine in ENL reaction is TNF-a.