Software-defined networking (SDN) enables microsegmentation by allowing administrators to create fine- grained, dynamic network segments at the software layer independent of physical network topology. This capability isolates workloads and controls traffic flows between segments, enhancing security within data centers and cloud environments. Next-generation firewalls (A) provide advanced filtering and inspection but do not inherently deliver the granular segmentation flexibility of SDN. Embedded systems (C) and air-gapped systems (D) refer to specific hardware or physical isolation techniques but do not implement microsegmentation as a network control method. The concept of microsegmentation through SDN is detailed in the Security Architecture domain of the SY0- 701 exam#6:Chapter 3 CompTIA Security+ Study Guide#.