<prompt> According to RNTCP, case definition on sputum ex- amination includes1 sample positive out of three samplesAt least two samples positive out of two samplesAny of the tw o or both samples are positive out of Iwo2 or 3 samples positive out of three  <response>: C Any of the two or both samples are positive out of two Two sputum smear samples are examined. If any of the two samples or both the samples are positive, the diagnosis of smear positive TB is confirmed. Diagnosis of pulmonary TB under RNTCP: Diagnosis is made primarily based on sputum smear examination. X-rays play a secondary role in the standard diagnostic algorithm for pulmonary tuberculosis Sputum smear microscopy, using the Ziehl-Neelsen staining technique, is employed as the standard case-finding tool. Two sputum samples are collected over two days as spot-morningmorning-spot from chest symptomatics patients with presenting with a history of cough for two weeks or more to arrive at a diagnosis. In addition to the tests high specificity, the use of two samples ensures that the diagnostic procedure has a high 99 test sensitivity as well. RNTCP pays more attention to the sputum-positive pulmonary tuberculosis patients who are likely to spread the disease in the community than people with other, non-pulmonary forms of the disease. 