Which element of the ArcGIS Pro user interface displays the contents of the active view?

The Contents pane is the element of the ArcGIS Pro user interface that displays the contents of the active view. This pane provides a hierarchical representation of all the layers, groups, and other elements that are currently displayed in the active map or scene. By using the Contents pane, users can easily manage the visibility and order of layers, as well as access properties for the selected layers, allowing for efficient organization and analysis of spatial data.

In contrast, the Catalog pane serves a different purpose by providing access to data, maps, and other resources in the project, but it does not show the contents of the active view. The Ribbon is the toolbar interface containing various tools and options for performing tasks, which is also distinct from displaying the active view's contents. Lastly, the View refers to the visual workspace itself where you can observe and interact with the data but does not encapsulate the descriptive, organizational qualities that the Contents pane offers. Thus, the Contents pane is essential for managing the elements that contribute to the active view’s data visualization.