Hola Anstor,
El comando es el siguiente:
neighbor {ip-address | peer-group-name} shutdown graceful seconds [ community value] [local-preference value] [community value] [ local-preference value]
Esta es la descripción del comando:
«The neighbor shutdown command terminates any active session for the specified neighbor or peer group and removes all associated routing information. In the case of a peer group, a large number of peering sessions could be terminated suddenly.
To display a summary of BGP neighbors and peer group connections, use the show ip bgp summary command. Those neighbors with an Idle status and the Admin entry have been disabled by the neighbor shutdown command. »
Básicamente ahí nos indican que si vemos el estado «idle» conjuntamente con «Admin», significa que el vecino fue deshabilitado con el comando shutdown. Para habilitarlo nuevamente simplemente tenemos que eliminar ese comando. Por ello que la respuesta correcta es C.
Saludos! =)