What connector is primarily used with unshielded twisted pair (UTP) cable?

The connector primarily used with unshielded twisted pair (UTP) cable is the RJ45 connector. UTP cables are commonly used in networking applications, including Ethernet connections, because they effectively reduce electromagnetic interference and crosstalk. The RJ45 connector, which typically has eight pins to accommodate the four pairs of wires found in a standard UTP cable, is designed specifically for these types of networks. It allows for a secure and efficient connection in data networking environments such as local area networks (LANs).

In contrast, the RJ11 connector is primarily used for telephone wiring and generally accommodates fewer wires, making it unsuitable for networking applications that require the higher bandwidth that UTP cables can provide. The DB9 connector is commonly found in serial connections used for devices like older modems or serial peripherals, while fiber connectors are designed for fiber optic cables, which use light to transmit data rather than electrical signals and are fundamentally different from UTP cabling technologies. Thus, RJ45 is the correct choice for UTP connections in networking scenarios.