What feature allows user interaction with additional business apps directly in Tableau?

The Extensions API is specifically designed to enhance user interactions by allowing the integration of additional business applications directly within Tableau. This feature provides the capability to create and embed web applications that can interact with Tableau visualizations. With the Extensions API, developers can build custom extensions that enable users to perform tasks such as data manipulation or accessing external data sources within the Tableau environment. This creates a more interactive and seamless user experience, as users can directly engage with supplementary tools and resources without leaving the Tableau interface.

In contrast, other options such as the Webhooks API primarily focus on sending real-time notifications about specific events in Tableau, while the Metadata API is used for extracting metadata about Tableau resources. The Analytics Extensions API allows for the integration of analytic models and external computations but does not facilitate the broader level of interactive application features that the Extensions API provides. This makes the Extensions API the correct choice for enabling user interaction with additional business apps in Tableau.