In bus topology, device which links all nodes in a network isRouterDropLineBackbonehub

In a bus topology, the correct answer to the question of which device links all nodes in a network is the Backbone.

Explanation

1. Bus Topology Overview: In a bus topology, all devices are connected to a single central cable, known as the "backbone." All communications between devices travel along this backbone.

2. Function of the Backbone: The backbone acts as a shared communication medium that transmits data between all connected devices (nodes). Unlike in star topology where a central hub or switch is used, in bus topology, the backbone directly facilitates the communication across all nodes.

3. Comparison with Other Options:

   • Router: This device directs traffic in a network but does not serve as the connecting medium in bus topology.
   • Drop Line: This refers to the individual connections from the backbone to each node, not the main linking device.
   • Hub: While it can serve a similar role in a star topology, it is not the proper terminology for bus topology where the backbone is the primary linking entity.

In summary, the backbone is the essential component of a bus topology that connects all devices, making it the correct answer.