23. Ralph is installing an Ethernet local area network (LAN) for a small business with two offices on opposite sides of a courtyard. Ralph plans to run a multimode fiber-optic cable across the courtyard, but the budget is limited, and he can’t use fiber for the whole network. Therefore, he installs unshielded twisted pair (UTP) cable in the two offices, which have ten and twelve workstations, respectively. Which of the following devices should Ralph use to join the two UTP installations together into one LAN using the fiber-optic run across the courtyard, while keeping the cost to a minimum?