What is the primary focus of examining 'population structure'?

The primary focus of examining 'population structure' is indeed the study of age and sex distribution within a population. This analysis is crucial because it provides insights into the demographic characteristics of a community, including the proportion of different age groups (such as children, working-age adults, and the elderly) and the balance between males and females.

Understanding age distribution helps in various planning aspects, including education, healthcare, and employment, as it indicates how many people will be entering or exiting various stages of life. For instance, a high proportion of young people suggests a future need for schools, while a larger elderly population might indicate an increased demand for medical care and retirement facilities. Additionally, sex distribution information can help in understanding gender dynamics and labor market participation.

This focus on age and sex distribution plays a critical role in shaping policies and resource allocation, making it a foundational aspect of demographic studies. Other options like understanding climate patterns, analyzing economic growth, or tracking migration trends, while significant in their own right, do not encapsulate the core concept of population structure as comprehensively as age and sex distribution does.