To let developers stage new application versions in production and let an outsourced operations team promote staged versions with minimal operational overhead, which Google Cloud product should you adopt?

App Engine is the correct choice because its built-in traffic splitting and versioning features directly support staging new application versions and promoting them with minimal operational overhead. This allows developers to deploy new code without impacting active users and operations teams to manage releases easily. GKE On-Prem (now Anthos on bare metal or VMware) is incorrect because it's for hybrid cloud deployments and doesn't inherently simplify application versioning and traffic management in the same way App Engine does for web applications. Compute Engine provides IaaS, requiring significant manual effort for versioning and traffic management. Google Kubernetes Engine (GKE) offers container orchestration but requires more configuration and management for blue/green deployments or canary releases compared to App Engine's integrated features.