Your Dataproc cluster is in a single subnet 172.16.20.128/25 with no available private IPs. To add new VMs that communicate with the cluster with minimal steps, what should you do?

Modifying the existing subnet range to 172.16.20.0/24 is the most straightforward solution. This expands the available IP addresses within the current subnet, allowing new VMs to be added without changing the network topology or introducing complex routing. The original /25 subnet (172.16.20.128-255) is a subset of the new /24 range (172.16.20.0-255), so existing resources will remain connected. Creating a new secondary IP range is not suitable for primary VM IPs; it's typically used for Pods or Services in GKE. Creating a new VPC and using VPC Peering would introduce unnecessary network complexity and management overhead for a simple IP exhaustion issue within a single cluster's subnet.