## **Core Concept**
The National Health Policy in India outlines the structure and coverage of various health facilities, including subcentres, which are the most peripheral and first contact point between the primary healthcare system and the community. Subcentres play a crucial role in providing basic medical and health services.

## **Why the Correct Answer is Right**
In hilly and tribal areas, the population density is generally low, and the terrain can be difficult, making access to healthcare more challenging. Given these geographical and demographic challenges, subcentres in such areas are designed to cater to a smaller population compared to plain areas. Typically, a subcentre in plain areas covers 5,000 population, whereas in hilly, tribal, or backward areas, it covers 3,000 population. This adjustment ensures that these vulnerable populations have adequate access to healthcare services.

## **Why Each Wrong Option is Incorrect**
- **Option A:** 5,000 population - This is the standard population covered by a subcentre in plain areas, not in hilly and tribal areas.
- **Option B:** 3,000 population - Although this seems like a plausible answer based on the correct information for hilly and tribal areas, we need to verify if it's listed as an option and ensure it matches the provided correct answer.
- **Option D:** 10,000 population - This is far beyond the typical coverage for a subcentre, even in plain areas.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the structure and coverage of health facilities like subcentres are adjusted based on the terrain and population characteristics. Specifically, subcentres in hilly and tribal areas cover 3,000 population, which is a critical piece of information for healthcare planning and policy.

## **Correct Answer:** B. 3,000.