Which network device is used to connect two or more network segments by performing OSI layer 3 functions like packet-forwarding?

The correct choice is the router because it operates at OSI layer 3, which is the network layer. Routers are designed to forward packets between different network segments, using IP addresses to determine the best path for data to travel across networks. This packet-routing capability is fundamental for connecting disparate networks or subnetworks and enabling communication beyond local segments.

In contrast, repeaters function at Layer 1 (the physical layer) and serve merely to regenerate and amplify signals to extend communication distances without making intelligent routing decisions. Wires themselves are merely the medium for transmission and do not perform any functions related to packet forwarding. Switches, while operating at Layer 2 (the data link layer), primarily manage data frames based on MAC addresses within a single network or local segment and do not route packets between different networks the way routers do. Thus, the router is the only device in the choices that performs the specified OSI layer 3 functions like packet-forwarding, connecting multiple network segments effectively.