01 What change is mainly explained by Demographic Transition Theory?
Answer and explanation
Correct answer: A. Shift from high birth and death rates to low birth and death rates
Explanation: Demographic Transition Theory describes a broad change in population behaviour during social and economic development. It mainly explains how a society moves from a situation with both high birth rates and high death rates to one with both low birth rates and low death rates. The theory focuses on the relationship between these two vital rates, not simply on migration, density, or political boundaries.
In the early stage, poor health care, sanitation, and food security can keep mortality high, while families may also have many children. With development, death rates usually fall first because survival improves. Later, education, urbanisation, changing family preferences, and access to contraception help reduce birth rates. Therefore, option A correctly states the central transition; the other choices describe narrower or unrelated changes.