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
[{'content': 'Main cytokine in ENL reaction: \nSelect and explain. \nA. TNF-a, B. IL-2, C. IFN, D. IL-12', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Main cytokine in ENL reaction is TNF-a.', 'role': 'assistant'}]