Final answer:
Star and bus topologies have a single point of failure due to their dependence on a central hub and a single communication line, respectively, while mesh does not because of its multiple interconnected paths.
Step-by-step explanation:
Among the network topologies mentioned - mesh, star, ring, and bus - the topologies that have a single point of failure are the star and bus configurations. In a star topology, all nodes are connected to a central hub or switch. If the central hub fails, the entire network goes down, creating a single point of failure. Conversely, in a mesh topology, each node is connected to every other node, which eliminates a single point of failure since multiple paths exist for data transmission.
Similarly, a ring topology does not have a single point of failure if implemented with a dual-ring or fault-tolerant setup, but a typical single-ring setup can be considered to have a single point of failure because if one connection breaks, the entire network can be disrupted. Finally, in a bus topology, all nodes are connected to a single communication line that carries messages in both directions. If this common backbone fails, all communications are halted, highlighting it as another single point of failure.