**Core Concept**
School health examination is a crucial aspect of preventive medicine, aimed at early detection and management of potential health issues in children and adolescents. It involves a comprehensive evaluation of physical, emotional, and social well-being to identify risk factors and provide appropriate interventions.

**Why the Correct Answer is Right**
The correct answer is focused on the age group of 5-18 years, as recommended by the World Health Organization (WHO) and the American Academy of Pediatrics (AAP). This age group is critical for identifying and addressing potential health concerns, including growth and development issues, nutritional deficiencies, and mental health problems. Regular school health examinations can help prevent the progression of these issues and ensure a healthy and productive life.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because children under 5 years may require more frequent and detailed health evaluations, especially in the first few years of life.
**Option B:** Incorrect as it does not specify the age range, which is a crucial factor in determining the frequency and scope of school health examinations.
**Option C:** Incorrect because it mentions an age group that may not require regular school health examinations, as they are typically considered adults.

**Clinical Pearl / High-Yield Fact**
It is essential for healthcare providers to understand the unique needs and challenges of each age group, and to tailor their approach accordingly. Regular school health examinations can help identify potential health concerns early, reducing the risk of long-term complications and improving overall health outcomes.

**Correct Answer:** D.