In age structure, children and elderly people are generally grouped together under which broad category?

Correct answer: Dependent population

Age structure classifies people by age and helps show how many are likely to work and how many may need support. Children are generally not yet in the labour force, while many older people have retired or have limited earning capacity. For this reason, both groups are commonly placed in the dependent population category, although actual dependence varies among individuals and societies.

Option B is correct because dependent population is the broad demographic category for people who are usually outside the working-age group. Working population refers mainly to people in economically active ages, not to children and the elderly together. Industrial and migrant population describe occupations or movement rather than an age-based dependency category. Thus B follows from the purpose of age classification and the usual relationship between age and economic support.