Multiple applications in your VPC connect to an on-premises database over a VPN. To avoid changing IP configuration in each application when the database IP changes, what should you do?

Creating a private Cloud DNS zone allows you to assign a stable DNS name to your on-premises database. If the database's IP address changes, you only need to update the DNS record in Cloud DNS, and all applications referencing the DNS name will automatically resolve to the new IP without requiring code changes. Configuring Cloud NAT is for managing outbound connections from your VPC and doesn't address internal IP resolution. Storing the IP in instance custom metadata would require updating metadata on every instance, which is cumbersome and less dynamic than DNS. Querying Compute Engine internal DNS is for resolving internal Google Cloud resources, not external on-premises databases.