How can an organization ensure applications are only installed from known trusted sources?

Disallowing unknown sources via policy using an EMM (Enterprise Mobility Management) is the most effective way to ensure applications are only installed from trusted sources. This EMM policy prevents users from sideloading applications from outside the Google Play Store or other approved app stores, thereby mitigating security risks associated with untrusted apps. Informing employees is a good practice but doesn't guarantee compliance. Google Play Protect scans for harmful apps but doesn't prevent their installation from unknown sources. Specifying device unlock or work profile security challenges enhances device security but doesn't directly control app installation sources.