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': 'Negative Mantoux test is when induration is \nSelect and explain. \nA. <10 mm, B. <15 mm, C. <20 mm, D. <5 mm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]