Okay, let's tackle this question about the population coverage of a Primary Health Center (PHC) in hilly areas. The user mentioned that the correct answer is option C, which I assume is 20,000. But wait, I need to make sure I remember the standard figures correctly.

First, the core concept here is about the infrastructure and population coverage ratios for PHCs in different terrains. In plains, a PHC typically serves 30,000-50,000 people, but in hilly or difficult areas, the population per PHC is lower. That's because hilly regions are harder to access, so the service area needs to be smaller to ensure accessibility.

The correct answer is 20,000. Why? Because according to the Indian Public Health Standards (IPHS), PHCs in hilly, tribal, and remote areas should cater to a smaller population due to the challenges in reaching these areas. The reasoning is that with more rugged terrain, it's impractical to cover the same number of people as in plains, so the population per PHC is reduced to 20,000.

Now, the wrong options. Let's say the options are A: 10,000, B: 15,000, C: 20,000, D: 30,000. Option D is for plains, so it's incorrect here. Option A might be for a Sub-Center, which serves around 5,000 people. Option B could be a distractor, perhaps for a Sub-Center in hilly areas. Wait, actually, Sub-Centers in hilly areas also have a smaller catchment. The standard is 20,000 for PHC in hilly areas. So A and B are incorrect because they are below or in between the standard figures for different levels.

The clinical pearl here is to remember that in difficult terrains, the population coverage for health centers is lower. A mnemonic could be "PHC in hills for 20K," contrasting with plains at 30-50K. Also, knowing the hierarchy: Sub-Center (SC) serves 5K, PHC serves 30-50K in plains, 20K in hills, and CHC (Community Health Center) serves a larger area.

I need to check if there are any other standards or if the IPHS has updated the numbers. But as per current knowledge, 20,000 is correct for hilly areas. So the explanation should highlight the terrain's impact on coverage and the specific IPHS guidelines. Also, clarify the roles of SC, PHC, and CHC in different terrains to avoid confusion with other options.

**Core Concept**
Primary Health Center (PHC) population coverage varies by terrain. In hilly/remote areas, a PHC serves a smaller population (20,000) compared to plains (30,000–50,000), as per Indian Public Health Standards (IPHS). This adjustment ensures equitable access to healthcare in geographically challenging regions.

**Why the Correct Answer is Right**
In hilly, tribal, or remote areas, the population per PHC is reduced to 20

✓ Correct Answer: B. 20000