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': 'Tuberculin test positive is dependent on - \nSelect and explain. \nA. Erythema, B. Nodule formation, C. Induration, D. Ulcerative change', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]