What network topology is used by ARCnet?

ARCnet, which stands for Attached Resource Computer Network, primarily utilizes a star topology in its design. In a star topology, all nodes are connected to a central hub or switch. This structure simplifies the network management and makes it easier to add or remove devices without disrupting the entire network.

Additionally, while the most common implementation of ARCnet is based on a star topology, it can also be configured to operate in a bus topology for specific applications. A bus topology involves connecting all devices to a single communication line, which can be efficient in certain scenarios but may lead to issues if the main line faces a failure.

Thus, option C accurately reflects the two topologies associated with ARCnet—star and bus—which explains why it is the correct answer. The star topology allows for a central connection point that is ideal for network stability and management, while the bus topology caters to different requirements depending on the environment and design preferences.