Which type of multipoint topology uses a common medium with multiple nodes attached?

The correct answer is the bus network, as this topology is characterized by a single central cable or "bus" that runs the length of the network, to which all devices (or nodes) are connected. In a bus network, each node can send and receive data over the shared medium, and any data sent by one node travels along the bus to reach all other nodes.

This simplicity in design allows for easy addition of new devices, as they can be connected directly to the bus. However, it is important for users to understand that this topology can be limited by the distance the bus can extend and the total number of nodes that can be connected before the performance decreases or network failure occurs.

Other options, like the star network, connect each node to a central hub, which means the medium is not shared in the same way as in a bus network. In a hierarchical topology, there is a more complex structure that often involves multiple layers of nodes rather than a simple shared bus system. The ring network connects nodes in a circular path, which also does not utilize a common medium shared among all nodes in the same fashion as a bus network does.