What does a population pyramid depict?

A population pyramid is a graphical representation of the distribution of various age groups in a population, typically displayed with males on one side and females on the other. This structure allows for clear visualization of the age and sex composition of a population at a specific point in time.

By examining a population pyramid, one can quickly identify trends such as whether a population is growing, stable, or declining. For example, a pyramid with a broad base indicates a high birth rate, while a more uniform or narrow pyramid represents lower birth rates and an aging population. Thus, it effectively demonstrates the age cohorts—different segments of age groups—and their corresponding sex ratios, making option B the most accurate description of what a population pyramid depicts.

This visualization does not directly illustrate economic factors, geographical distributions, or historical changes in population size, which distinguishes the correct option from the others.