Which devices break up collision domains?

• A. Hubs And Repeaters.
• B. Routers And Switches.
• C. Bridges.
• D. End-User Devices.

Answer: (B)

Collision domains are network segments where data can collide if two devices transmit simultaneously. Hubs and repeaters don’t partition these domains—they simply extend the same shared medium, so all devices attached to them share one collision domain. End-user devices are endpoints and don’t create their own separate collision domains.

Routers and switches do create boundaries. A switch gives each of its ports its own collision domain, so devices on different ports cannot collide with each other through the switch. A router takes this further by separating networks at layer 3, with each router interface acting as its own collision domain. Therefore, routers and switches are the devices that break up collision domains.

Bridges also separate collision domains by segmenting LANs, but in common exam contexts the emphasis is on routers and switches as the primary devices that accomplish this in typical LAN designs.