**Core Concept:** Principles of Primary Health Care (PHC) refer to a holistic approach to healthcare, which emphasizes on accessibility, availability, and acceptability of healthcare services for the entire population. These principles include preventive care, community participation, and integration of health services.

**Why the Correct Answer is Right:** The correct answer, **D**, refers to a specific principle that is not part of the principles of primary health care. This principle is "individualized treatment" or "personalized medicine." In contrast to PHC, personalized medicine focuses on tailoring treatment plans based on the patient's unique genetic makeup, lifestyle, and disease characteristics. This is a recent development in medicine that goes beyond the primary health care principles of accessibility, community participation, and integrated services.

**Why Each Wrong Option is Incorrect:**

A. **Group health education and promotion:** This principle is a part of primary health care, focusing on empowering communities and individuals through education and awareness programs to improve health outcomes.

B. **Community participation:** Community participation is another essential principle of primary health care, involving local communities and stakeholders in planning, implementing, and evaluating health programs.

C. **Integration of health services:** Integration of health services is a principle of primary health care, ensuring that various levels of healthcare services work together to provide comprehensive and coordinated care for patients.

**Clinical Pearl / High-Yield Fact:** The principles of primary health care, including community participation, integration of health services, and health education and promotion, are critical for improving public health outcomes and addressing the health needs of entire communities, which is essential for public health systems. Understanding these principles helps in planning, implementing, and evaluating healthcare strategies effectively.