Software Defined Networking $($SDN$)$ uses a controller to manage devices. The controller is able to inventory hardware components on the network, gather network statistics, make routing decisions based on gathered data, and facilitate communication between devices from different vendors. It can also be used to make widespread configuration changes on just one device. Which of the following BEST describes an SDN controller? answer The SDN controller is hardware. The SDN controller is a networking protocol. The SDN controller is software. The SDN controller is a virtual networking device.