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: Microbiology
[{'content': 'One of the following is an agglutination test in the diagnosis of typhoid: \nSelect and explain. \nA. Wide test, B. Eleks test, C. Mantoux test, D. Wasserman test', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]