The question requires following Google's recommended practices for production-level applications. Based on the community discussion and Google documentation, option D is the correct choice because it implements the production-level topology with four Dedicated Interconnect connections across two metros in different metro zones, providing 99.99% availability, which exceeds the minimum 99.9% requirement and ensures high performance and redundancy. Option A (Partner Interconnect) only provides 99.9% availability and is suitable for non-critical applications, not production-level. Option B (VPN) is insecure and insufficient for high-performance needs due to internet-based traffic. Option C (Direct Peering) is intended for Google Workspace, not Google Cloud connectivity. The consensus in the discussion, supported by upvoted comments and references to Google's best practices, confirms D as optimal.