Explanation
The question asks about the latitudinal belt where about 50% of the world population is concentrated.World population distribution is highly uneven. The vast majority of people live in the Northern Hemisphere.Major population clusters are found in East Asia (China, Japan, Korea), South Asia (India, Pakistan, Bangladesh), Southeast Asia, Europe, and Eastern North America.Let's examine the options:(A) 5°N and 20°N: Includes parts of Africa, South India, Southeast Asia, Central America. High population but unlikely to hold 50%.(B) 20°N and 40°N: This belt covers North Africa, the Middle East, North India, most of China, Southern Europe, and the Southern/Central USA. This zone encompasses several major population centres (especially China and North India) and represents a significant portion of the world's land area suitable for agriculture and settlement. It is widely cited that a large majority of the world's population lives between 20°N and 60°N, with the 20°N to 40°N band containing a very high concentration, likely close to or encompassing the 50% mark.(C) 40°N and 60°N: Includes most of Europe, Russia, Canada, Northern USA. Densely populated in Europe but large sparsely populated areas (Siberia, Canada).(D) 20°S and 40°S: Includes Southern Africa, parts of South America (Brazil, Argentina, Chile), and Australia. Population density is much lower compared to the Northern Hemisphere belts.Therefore, the latitudes between 20°N and 40°N host the highest concentration of the global population.