Here,s why the other statements are inaccurate:
A). BGP automatically learns routes between DRGs without any configuration: This is false. While BGP facilitates dynamic routing exchange, it requires configuration to establish peering sessions and define how routes are exchanged between DRGs.B. You only need to configure BGP on the DRG connected to the on-premises network: This is false. BGP needs to be configured on all DRGs participating in the transitive routing, not just the one connected to the on-premises network. Each DRG needs to exchange routing information with other DRGs to enable traffic flow across regions.C. All DRGs involved must use the same BGP AS number for route exchange: This is false. While using the same AS number simplifies configuration, it,s not mandatory. DRGs can have different AS numbers and exchange routes through BGP peering as long as the peering agreements and route policies are properly configured.