Requirement: Transitive routing across regions and to on-premises, privately. Components: LPG: Intra-region VCN peering; limited scope. DRG: Cross-region and on-premises routing via private backbone. Service Gateway: OCI service access; not transitive. Internet Gateway: Public internet; not private. Evaluate Options: A: Region-specific; incorrect. B: Supports multi-region and on-premises; correct. C: Service-focused; incorrect. D: Public; incorrect. Conclusion: DRG is the key component. DRG enables complex routing scenarios. The Oracle Networking Professional study guide notes, "The Dynamic Routing Gateway (DRG) facilitates transitive routing between VCNs in different regions and on-premises networks over OCI’s private backbone" (OCI Networking Documentation, Section: Dynamic Routing Gateway). This meets both requirements efficiently.
Reference: Oracle Cloud Infrastructure Documentation - Dynamic Routing Gateway.