**Core Concept**
Primary health care (PHC) is a holistic approach to healthcare that emphasizes community participation, accessibility, and equity. It is a comprehensive set of services that address the physical, mental, and social health needs of individuals and communities.

**Why the Correct Answer is Right**
The correct elements of primary health care include health education, nutrition, maternal and child health care, disease prevention and control, and promotion of healthy living. These elements are crucial in addressing the root causes of health problems and improving overall well-being. The World Health Organization (WHO) has identified these elements as essential components of primary health care.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not a recognized element of primary health care. While surgery is an essential medical service, it is typically provided at the secondary or tertiary level of care, rather than as a primary health care service.
**Option B:** This option is not accurate. Health education is indeed an element of primary health care, but it is not the only one. There are several other key components that are essential for comprehensive primary health care.
**Option C:** This option is not correct. While family planning is an important aspect of reproductive health, it is not a standalone element of primary health care. It is often integrated into broader health education and promotion services.

**Clinical Pearl / High-Yield Fact**
When considering primary health care, remember that it is not just about treating illnesses, but also about preventing them. By focusing on health promotion, disease prevention, and community participation, primary health care can have a profound impact on improving health outcomes and reducing health inequities.

**Correct Answer: D. Surgery**