An enterprise solution team is analyzing multilayer architecture and multicontroller SDN solutions for multisite deployments.

B (East-West API between controllers):In multicontroller SDN architectures, East-West APIs allow controllers to synchronize state, policies, and tasks, enabling distributed control while presenting a unified control plane view. This ensures that tasks can be performed on any controller consistently.

Other options explained:

A: Root controllers are not standard in modern SDN distributed architectures.

C: Physical connectivity alone doesn ' t synchronize state or tasks.

D: OpenFlow governs switch forwarding, not controller-to-controller interaction.