Which of the following network topologies forms a closed loop?

The correct answer is the network topology that forms a closed loop is the ring topology. In a ring topology, each device is connected to exactly two other devices, creating a circular data path. As a result, data travels in one direction along the ring until it reaches its destination, making it a closed loop. This structure can help in reducing collision domains and can also simplify the process of sending data from one node to another.

While other topologies have their own unique features, they do not form a closed loop in the same manner. For instance, in a star topology, all devices are connected to a central hub or switch, leading to a star-like formation that does not have a continuous loop. In a mesh topology, every device is interconnected, but this does not imply a singular continuous path; rather, it enhances redundancy and reliability. Lastly, in a bus topology, devices are connected to a single central cable, and while data can flow in both directions along the bus line, it lacks the loop structure characteristic of a ring topology. Thus, the defining feature of a closed loop is specific to the ring topology, making it the correct answer.