Refer to the exhibit. R1 and R2 are directly connected, but the BGP session does not establish. Which action must be taken to build an eBGP session?

Configuring a static route for R1's loopback (1.1.1.1) via a directly connected interface (192.168.12.1) is generally not required for directly connected eBGP neighbors, as reachability is implicitly handled by the connected subnet.

The `activate` command is usually implicitly enabled for directly connected eBGP neighbors when the `neighbor remote-as` command is configured and is typically required only when peering over loopback interfaces with an `update-source` command.

Configuring `neighbor 2.2.2.2 remote-as 65002` under R1's BGP process would be a valid configuration step if R2's loopback is 2.2.2.2, but the question implies a specific missing action to build the session, and option D addresses an administrative shutdown state which is a more fundamental impediment.

If the BGP neighbor 192.168.12.1 is administratively shut down on R2, which is a common reason for a session not establishing, the `no neighbor 192.168.12.1 shutdown` command will reactivate the BGP peering process. This action allows the router to attempt to establish a BGP session with its neighbor.