Which topology uses a single trunk, or backbone, that connects all devices?

• A. Bus Topology
• B. Star Topology
• C. Mesh Topology
• D. Hybrid Topology

Answer: (A)

The defining idea here is a single shared communication line, called the backbone, that every device connects to. In a bus topology, each device taps into one continuous cable, and signals travel along that trunk so all devices can hear transmissions. Because the medium is shared, devices must coordinate access and collisions can occur, which historically required collision detection and, at the ends of the line, termination to prevent signal reflections. This setup is typically associated with coaxial cable and older Ethernet implementations, where the trunk tied all stations together along one path. While it's straightforward to install and uses less cable, it scales poorly and a problem on the backbone can take down the whole network. This explains why it’s distinct from star topology, where devices connect to a central hub, from mesh topology, which features multiple redundant paths among devices, and from hybrid topology, which blends elements of different designs.