**Core Concept**
Annual Risk of Incidence (ARI) refers to the proportion of individuals in a population who develop new tuberculosis (TB) cases annually. It is a key metric in public health for estimating TB burden and planning interventions.

**Why the Correct Answer is Right**
The Annual Risk of Incidence (ARI) represents the probability of a person developing a new TB case in a year. It is calculated based on actual observed new cases in a population, not through tuberculin conversion. In India, the current ARI is approximately 1.7%, and a 1% ARI corresponds to about 75 new cases per 100,000 population. However, ARI is derived from clinical diagnosis and epidemiological surveillance, not from tuberculin skin test (TST) conversion, especially in vaccinated individuals. The use of tuberculin conversion is not a valid method for assessing ARI in non-vaccinated children, as it may miss latent infections and is not standardized for population-level incidence estimation.

**Why Each Wrong Option is Incorrect**
Option A: A 1% ARI does not equal 75 new cases — this is incorrect because ARI is a rate per 100,000, and 1% of 100,000 is 1,000 cases, not 75. The statement is false and thus contradicts the premise.
Option B: The current ARI in India is not 1.7% — this is factually incorrect; the actual ARI in India is around 1.7%, making this statement true.
Option C: ARI represents new cases of TB — this is accurate and correct, so it is not the right choice to be "not false."

**Clinical Pearl / High-Yield Fact**
ARI is a population-level estimate of new TB cases, derived from surveillance data, not skin test conversion. Tuberculin conversion is used for diagnosing latent TB infection, not for calculating annual incidence rates.

✓ Correct Answer: D. It is assessed by tuberculin conversion in previously non-vaccinated children