正解:D
Cisco Modeling Labs (CML) is a network simulation tool that allows users to create, configure, and simulate networks with Cisco devices and topologies.
* Cisco Modeling Labs (CML): CML provides a virtual environment where users can simulate network topologies and devices, including routers, switches, and other network components.
* Simulation and Testing: CML allows users to test configurations, troubleshoot network issues, and study network behavior in a controlled environment.
References:
* Cisco Modeling Labs: Cisco Modeling Labs