What does an age-structure diagram with a pyramidal shape (showing a prevalence of younger individuals, many of reproductive age), indicate? a. A slowly expanding population b. A stable population c. A declining population d. A rap

d. A rapidly expanding population An age-structure diagram with a pyramidal shape, featuring a large base of younger individuals and many individuals in the reproductive age group, indicates a rapidly expanding population. This shape suggests that a high birth rate is present, leading to more young people compared to older age groups.