Requirement: Private VCN connection across tenancies. Services: Internet Gateway: Public access; incorrect. Service Gateway: OCI services, not VCNs; incorrect. RPC: Cross-tenancy private peering; correct. DRG with LPG: LPG is intra-region, not cross-tenancy; incorrect. Evaluate Options: A: Public; incorrect. B: Service-focused; incorrect. C: Designed for this scenario; correct. D: Misaligned components; incorrect. Conclusion: RPC is the right service. RPC enables cross-tenancy peering. The Oracle Networking Professional study guide notes, "Remote Peering Connections (RPCs) establish private connectivity between VCNs in different tenancies over OCI’s private backbone" (OCI Networking Documentation, Section: Remote Peering Connections). This ensures no public internet traversal.
Reference: Oracle Cloud Infrastructure Documentation - Remote Peering Connections.