Which visualization option in Power BI displays data as a set of nested rectangles?

The visualization option that displays data as a set of nested rectangles is the treemap. Treemaps are particularly effective for visualizing hierarchical data as they allow viewers to see both the size of nested categories and their relationships within a compact space. Each rectangle represents a data point, and its size is proportional to its value, enabling easy comparison among different categories simultaneously.

A treemap organizes data in a way that allows for intuitive understanding of proportions and relationships, which is especially useful when dealing with large volumes of data or multiple dimensions. This type of visualization helps in identifying patterns and outliers in the dataset, offering a comprehensive view that might be lost in more linear visualizations like bar or column charts.

Bar charts and column charts display data in linear formats, focusing on individual values rather than the hierarchy and composition that a treemap highlights. Slicers serve a different function entirely, as they are interactive filters that help refine the data being displayed but do not visualize data in the form of nested rectangles.