## Core Concept
Primary health care (PHC) is an essential health care approach that is based on practical, scientifically sound, and socially acceptable methods. It is universally accessible to individuals and families in the community through their full participation and at a cost that the community and country can afford. The core concept of PHC includes health promotion, disease prevention, diagnosis, treatment, and rehabilitation.

## Why the Correct Answer is Right
The correct answer, , implies that the statement regarding primary health care being accessible and affordable is a fundamental principle. PHC aims to provide comprehensive care that is accessible and affordable to all, emphasizing community participation and equity.

## Why Each Wrong Option is Incorrect
- **Option A:** If option A describes a fundamental aspect of PHC such as accessibility, affordability, or community participation, then it would be correct and not the answer.
- **Option B:** Similarly, if option B aligns with PHC principles like equity, intersectoral collaboration, or appropriate technology, it wouldn't be the incorrect statement we're looking for.
- **Option D:** If option D also represents a true statement regarding PHC, such as its focus on health promotion and disease prevention, then it doesn't fit as the "except" part of the question.

## Clinical Pearl / High-Yield Fact
A key point to remember is that primary health care is the first level of contact between the individual and the healthcare system, bringing health care as close as possible to where people live and work. It is a critical component of a country's health system and, ideally, its main focus. The **"Health for All"** initiative by the World Health Organization (WHO) underscores the importance of PHC in achieving equitable health outcomes.

## Correct Answer: D.