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
Which of the following is not false about annual risk of TB 
Select and explain. 
A. ARI of 1% = 75 new cases, B. Current ARI in India is 1.7%, C. It is represents new cases of TB, D. It is assessed by tuberculin conversion in previously non-vaccinated children
D: It is assessed by tuberculin conversion in previously non-vaccinated children
Answer: D: It is assessed by tuberculin conversion in previously non-vaccinated children 
Explanation: Incidence of TB infection (Annual infection rate, Annual risk of Infection ARI) : Percentage of population under study who will be newly infected (not diseased or cases) with TB among Non-infected in 1 year. Expresses attacking force of TB in community In developing countries 1% ARI corresponds to: 50 SS +ve cases per 100,000 general population Tuberculin conversion index is the "best indicator for evaluation of TB problem and its trend" in the community. Current ARI in India : 1.5% Ref: Park 25th edition Pgno : 190-191