Which of the following options is used for featuring the navigation menu in a sidebar?

The Atlas Default represents the design framework used in Mendix applications and provides a modern, responsive layout. This design framework includes a built-in sidebar navigation menu, allowing users to easily navigate through various sections of the application. The sidebar is particularly effective for providing a clear and organized structure, as it supports the inclusion of multiple navigation options in a compact space.

When utilizing the Atlas Default, developers can leverage the pre-defined styles and components, streamlining the development process while ensuring a consistent user experience across different pages of the application. The sidebar menu enhances usability by keeping important navigation elements readily accessible, thus facilitating a smoother user journey.

While other options may offer different styles of navigation, they do not specifically indicate a sidebar layout encapsulated within the Atlas Default structure.