Which one of the following is NOT an area of sparse population?

South Asia

The correct answer is Option (4) → South Asia

South Asia (including countries like India, Bangladesh, Pakistan, etc.) is one of the most densely populated regions in the world. In contrast, the Kalahari Desert, Central Asia, and Equatorial regions (like the Amazon Basin and Congo) are known for sparse population due to harsh climates, dense forests, or rugged terrain.