This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'Case finidng in RNTCP is based on - \nSelect and explain. \nA. Sputum culture, B. Sputum microscopy, C. X-ray chest, D. Mantoux test \\/ PCR', 'role': 'user'}, {'content': "Answer: B \nExplanation: - the case finding tool in RNTCP is based on sputum examination. - sputum smear examination by direct microscopy is now considered the method of choice. Reference : Park's textbook of preventive and social medicine, 23rd edition, pg no:429 <\\p>", 'role': 'assistant'}]