What is one example of an ARIA role that must have specific children?

The correct answer highlights the ARIA role "Radiogroup," which is required to have specific children with the role "radio." In the context of accessibility, the radiogroup role is designed to manage a set of options where only one can be selected at a time. This is typically used in situations like radio buttons in forms.

The radiogroup acts as a container, while the role of radio indicates each individual option within that group. This hierarchical relationship is crucial for assistive technologies to properly convey the available choices to users with disabilities. If a radiogroup does not contain roles of radio, it fails to fulfill its purpose, leading to confusion and hindering user navigation.

In contrast, other roles like tab and list do not have as stringent requirements regarding their children roles. While tab panels can have numerous forms of content within them, they do not specifically mandate the inclusion of tabs with the role panel, nor do lists strictly require options as children. Therefore, the requirement for a radiogroup to only include radio roles is a specific stipulation that is essential for maintaining correct semantic structure and facilitating proper interaction for users relying on assistive technologies.