Which of the following statement is incorrect in the context of "Age Structure"?

None of the above

The correct answer is Option 4: None of the above

Option 1: The age structure of the population refers to the proportion of persons in different age groups relative to the total population. Correct. Age structure is concerned with how a population is distributed across different age categories. It helps demographers understand whether a population is relatively young, ageing, or balanced across age groups.

Option 2: The age structure changes in response to changes in levels of development and the average life expectancy. Correct. Improvements in healthcare, nutrition, sanitation, and living conditions influence mortality patterns and life expectancy, which in turn alter the age composition of the population.

Option 3: With development relatively smaller proportions of the population are found in the younger age groups and larger proportions in the older age groups. Correct. As mortality declines and people survive to older ages, the share of older persons increases. This process is commonly known as population ageing.

NCERT: "The age structure of the population refers to the proportion of persons in different age groups relative to the total population. The age structure changes in response to changes in levels of development and the average life expectancy. Initially, poor medical facilities, prevalence of disease and other factors make for a relatively short life span. Moreover, high infant and maternal mortality rates also have an impact on the age structure. With development, quality of life improves and with it the life expectancy also improves. This changes the age structure: relatively smaller proportions of the population are found in the younger age groups and larger proportions in the older age groups. This is also referred to as the ageing of the population."