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: Social & Preventive Medicine
[{'content': 'Confirmatory Test for coliform count \nSelect and explain. \nA. Eijkman test, B. Casoni’s test, C. Nitrate test, D. Urease test', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]