## **Core Concept**
The Revised National Tuberculosis Control Programme (RNTCP) provides guidelines for the population covered by a Tuberculosis Unit (TU) based on geographical and demographic considerations. In hilly or difficult areas, the population density and accessibility vary, necessitating adjustments in the coverage area of a TU.

## **Why the Correct Answer is Right**
In hilly areas, due to terrain difficulties and lower population density, one Tuberculosis Unit (TU) is recommended to cover a population of 20,000. This adjustment ensures equitable access to TB diagnosis and treatment services despite the challenging geography. A TU typically serves as a critical administrative and operational unit for delivering TB control services.

## **Why Each Wrong Option is Incorrect**
- **Option A:** 5,000 - This is too low for hilly areas; typically, one TU covers a larger population in such regions.
- **Option B:** 10,000 - This is still lower than the recommended population for hilly areas.
- **Option D:** 30,000 - This exceeds the recommended population for a TU in hilly areas.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the RNTCP recommends one TU for 20,000 population in hilly or difficult areas, in contrast to plain areas where one TU covers 15,000 population. This distinction is crucial for planning and delivering TB control services effectively.

## **Correct Answer:** . 20,000