This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'Tube agglutination test is used for serological diagnosis for \nSelect and explain. \nA. Enteric fever, B. Rabies antigen, C. HIV, D. Syphilis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tube agglutination test is useful for serological diagnosis of enteric fever, typhus fever, infectious mononucleosis Ref: Textbook of Microbiology Baveja 5th ed Pg 120', 'role': 'assistant'}]