The question asks which OTV edge device configuration allows two OTV edge devices located in the same site to bring up the dual-site adjacency. According to the correct setup for OTV, the primary edge device should have the 'otv adjacency-server unicast-only' configuration, while the secondary device should be configured to use the primary's adjacency server with 'otv use-adjacency-server unicast-only'. This configuration ensures that one device acts as the primary adjacency server while the other uses it. Option B demonstrates this setup properly. In Nexus-1, 'otv adjacency-server unicast-only' is set up, making it the primary, and in Nexus-2, 'otv use-adjacency-server 20.1.1.1 unicast-only' is configured, linking it to the primary. Therefore, Option B is the correct answer.