Which statement best describes a northbound REST API for SDN?

A northbound REST API in SDN is an application-facing interface. This means it allows applications and orchestration systems to programmatically interact with the SDN controller to request network services, provision resources, and monitor network status. It uses standard HTTP methods like GET (retrieve information), POST (create resources), PUT (update resources), and DELETE (remove resources) to perform these operations. The incorrect options describe: "Network-element-facing interface for GET, POST, PUT, and DELETE methods": This describes a southbound API, which communicates with network devices. "Application-facing interface for SNMP GET requests": While SNMP is application-facing, it's a legacy protocol and not the primary mechanism for northbound REST APIs in modern SDN. "Network-element-facing interface for the control and data planes": This also describes a southbound API, specifically how the controller interacts with network devices to manage forwarding and control logic.