The Prod-DB virtual mavhine has a VM Override as shown in the Exhibit: What step, if taken, would require all virtual machines in the cluster to migrate automatically?

The Host Isolation Response governs VM behavior during a network isolation event and has no effect on DRS automatic migration scheduling.

Deselecting a single VM from VM Overrides only removes that one VM's custom settings and does not affect the migration behavior of all other VMs in the cluster.

Adding all VMs to VM Overrides creates individual per-VM settings but does not itself configure those VMs to automatically migrate - each override would still require separate configuration.

When a VM Override's Automation Level is set to 'Use Cluster Settings,' that VM inherits the cluster's DRS automation level; if the cluster is configured as Fully Automated, DRS will automatically migrate all VMs - including the previously overridden one - based on load balancing recommendations.