Which of these factors is critical for understanding population issues in a country?

Accurate demographic data from various sources is crucial for understanding population issues in a country because it provides a comprehensive and factual foundation for analyzing population trends and dynamics. This data includes information on birth rates, death rates, age distribution, migration patterns, and other vital statistics that help in assessing the overall demographic structure of a population.

Demographic data allows policymakers, researchers, and analysts to identify and address key population challenges, such as aging populations, urbanization, and migration issues. Without precise and reliable demographic data, it becomes difficult to make informed decisions regarding resource allocation, social services, healthcare, and education that cater to the needs of the population.

While annual economic growth rates, trends in social media usage, and changes in public transportation systems can influence or reflect certain aspects of a population's situation, they do not provide the fundamental insights required to understand demographic changes and their implications fully. Economic data may reflect prosperity but does not always correlate directly with population dynamics, and social media trends can be quite fluid and not indicative of deeper demographic issues. Changes in transportation systems may affect mobility and urbanization but lack the essential demographic elements that direct population analysis.