Final answer:
SDN is an intelligent network architecture where a software controller assumes control over the network's control plane functionality, providing greater flexibility and programmability of network devices.
Step-by-step explanation:
The correct answer is a) SDN, which stands for Software-Defined Networking. SDN is an intelligent network architecture where a software controller assumes control over the network's control plane functionality. This controller centralizes the management and control of the network, allowing for greater flexibility, efficiency, and programmability of network devices.
SDN separates the control plane from the data plane, enabling network administrators to programmatically define how the network packets should be forwarded. It provides a centralized view of the network, making it easier to configure, manage, and monitor network devices.
This contrasts with traditional network architectures where the control plane and data plane are integrated within the network devices themselves. In an SDN architecture, the controller operates at the control plane level, managing traffic and device configurations across the entire network, irrespective of the underlying hardware.
For example, in an SDN architecture, if a network administrator wants to change the routing policy of the network, they can do so by modifying the instructions within the software controller, rather than having to manually configure each network device individually.