This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: RNTCP, Subject name: Social & Preventive Medicine
[{'content': 'Best indicator of trend of Tuberculosis unaffected by current control measures is:- \nSelect and explain. \nA. Annual risk of infection, B. Prevalence of TB infection, C. % of primary drug resistance, D. % of multidrug resistance', 'role': 'user'}, {'content': "Answer: A \nExplanation: Annual risk of infection: Is the propoion of population which will be primarily infected with tuberculosis in course of 1 year. Is incidence of infection of TB. Is known as 'Tuberculosis conversion Index'. Best indicator of trend of TB unaffected by current control measures. ARI: 1-2%. For every 1% rise of ARI, there are 50 SS +ve cases /Lac population.", 'role': 'assistant'}]