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': 'The best diagnostic procedure of M.tuberculosis \nSelect and explain. \nA. PCR, B. Auramin rhodamin stain, C. Sputum culture, D. ESR', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. is \'c\' i.e., Sputum culture "Definitive diagnosis depends on isolation (culture) and identification of M. tuberculosis from a diagnostic sepcimen (most common specimen in sputum)".', 'role': 'assistant'}]