**Question:** Which of the following stages of demographic cycle has declining population:

A. Neonatal
B. Infancy
C. Childhood
D. Adolescence

**Correct Answer:** D. Adolescence

**Core Concept:** Demographic cycle refers to the changes in population size and composition over time, including four stages:

1. Neonatal stage: This stage encompasses the first four weeks of life, characterized by rapid growth and development.
2. Infancy: From the fifth week to the first birthday, infants undergo significant growth and development.
3. Childhood: This stage covers the period from the first birthday to adolescence, characterized by continued growth and development.
4. Adolescence: This stage begins at puberty and continues through young adulthood, marked by changes in physical, psychological, and social development.

**Why the Correct Answer is Right:** Adolescence is the stage with declining population due to the transition from childhood to adulthood. During this period, fertility rates decrease, and individuals are more susceptible to various health issues such as sexually transmitted infections, unintended pregnancies, and mental health disorders. This leads to a decrease in the overall population growth rate.

**Why Each Wrong Option is Incorrect:**

A. Neonatal stage: This stage has a high mortality rate, particularly due to infectious diseases, but population growth rate is high.
B. Infancy: Similar to neonatal stage, infancy has a high mortality rate but a growing population due to high fertility rates.
C. Childhood: Although fertility rates are high during childhood, the focus should be on the declining population in adolescence, not in childhood.

**Clinical Pearl:** Understanding the demographic cycle helps inform public health policies, resource allocation, and disease prevention strategies. In developing countries, addressing adolescent health issues and promoting family planning can contribute to reducing mortality and improving overall population health.