Which of the following is NOT a reason for population explosion?

Correct option is D

Overcrowding is a result of population explosion, not a cause. Population explosion occurs due to several contributing factors such as early marriage, lack of education, high fertility rates, and religious or cultural resistance to contraception. These factors lead to increased birth rates, whereas overcrowding is a condition that emerges as a consequence of overpopulation in a region.
Explanation of options: (a) Early marriage – This is a contributing factor as it increases the reproductive span of individuals, leading to higher birth rates. (b) Illiteracy – Lack of education often results in poor awareness and use of family planning methods, contributing to population growth. (c) Religious beliefs and traditions – These can influence people's choices regarding contraception and family size, promoting larger families. (d) Overcrowding – This is the correct answer. It is a consequence, not a cause, of population explosion.