Which statement best describes what the bars illustrate?

• A. The number of births per year
• B. The distribution of population by age and sex
• C. The total population at each time point
• D. The numbers of people added to the population annually in each decade

Answer: (B)

These bars show the age and sex structure of a population. Each bar corresponds to a specific age interval, and the bar is typically split to display the number of people of each sex in that age range. The length of each bar indicates how many individuals are in that age group, so the chart reveals how the population is distributed across ages at a given time. This is different from births per year (a time-series count), the total population at a moment (which would require summing across all bars), or the number added each decade (which would track changes over time, not the current age structure). So the bars best describe the distribution of population by age and sex.