## **Core Concept**
The World Health Organization (WHO) defines various age groups for humans, including adolescents. Adolescence is a critical phase of growth and development, characterized by significant physical, psychological, and social changes.

## **Why the Correct Answer is Right**
The correct answer, **10-19 years**, is defined by the WHO as the age range for adolescents. This phase is crucial for growth and development, marked by the onset of puberty and the transition from childhood to adulthood. The WHO's definition is widely accepted and used in public health and medical practices.

## **Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not accurately reflect the WHO's definition of adolescent age.
* **Option B:** This option is incorrect as it represents a broader age range that includes children and adults, not specifically adolescents.
* **Option D:** This option is incorrect because it only partially covers the adolescent age range defined by the WHO.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the adolescent age range, as defined by the WHO, is **10-19 years**. This is essential for healthcare providers and educators to identify and address the unique needs of this age group.

## **Correct Answer:** . 10-19 years