What do routers break up and is defined as a portion of a network limited by its router connection to a specific group of host computers in a common LAN segment?

• A. Collision Domains
• B. Subnets
• C. Virtual Networks
• D. Broadcast Domains

Answer: (D)

Routers divide a network into separate broadcast domains. A broadcast domain is the set of devices that receive broadcast frames from any device within that domain, and a router will not forward broadcast traffic from one LAN segment to another. This means each router interface defines a boundary, so the portion of the network described—limited by the router connection to a specific group of hosts on a common LAN segment—matches the concept of a single broadcast domain.

In contrast, collision domains relate to how devices contend for access on shared physical media; switches can segment them, but routers are what create the boundary for broadcast domains. Subnets pertain to IP addressing and routing boundaries, which is related but about logical network addressing rather than the broadcast reach. Virtual networks (often implying VLANs) are another abstraction that can also partition broadcast domains, but the direct match for the described boundary is the broadcast domain.