Objective: Enable transitive routing via a network appliance (e.g., firewall) between VCNs. Transitive Routing Setup: DRG connects VCNs; appliance processes traffic. Key Requirement: DRG must route traffic to the appliance’s private IP. Evaluate Options: A: Service Gateway is for OCI services, not transitive routing; incorrect. B: Static routes on DRG to appliance ensure correct traffic flow; essential. C: Load Balancer is optional, not essential for routing; incorrect. D: LPG is for intra-region VCN peering, not appliance-DRG connection; incorrect. Conclusion: DRG static routes to the appliance are critical for transitive routing. Transitive routing with a network appliance requires explicit routing configuration. The Oracle Networking Professional study guide notes, "To enable transitive routing through a network appliance, configure static routes in the DRG route table pointing to the appliance’s private IP as the next hop" (OCI Networking Documentation, Section: Transitive Routing with DRG). This ensures traffic is processed by the appliance between VCNs.
Reference: Oracle Cloud Infrastructure Documentation - Dynamic Routing Gateway.