In RNTCP the most effective tool for case finding is:

Ans: A (Sputum examination) Ref: Park 22nd editionExplanation:The case finding tool in RNTCP is Sputum examination.In the previous program NTP there was over reliance on X-ray as the case finding tool.X-ray had low specificity and had lot of difference in opinion in reporting of the X-ray (poor inter rater reliability), hence the case finding tool in RNTCP is sputum examination.In RNTCP, X-ray is used only to diagnose a small proportion of cases such as - sputum negative cases and extra pulmonary tuberculosis such as pleural and pericardial effusion.