What is the correct testing track to test private apps?

The Closed Track is the correct option for testing private apps because it specifically allows you to assign the track to organizations for Google-hosted private apps and publish them to managed Google Play. This enables controlled distribution to a defined set of testers within an organization, which is essential for private app testing. The Internal Track is primarily for quick internal distribution and quality assurance, but it doesn't offer the organizational assignment and managed Google Play publishing capabilities needed for formal private app testing. The Open Track makes the app's test version available on Google Play, which is unsuitable for private apps that should not be publicly discoverable. While all tracks can technically handle public and private apps, only the Closed Track provides the necessary features for secure and controlled private app distribution and testing within an enterprise context.