Which of the following is most commonly used to connect devices to a switch?

The CompTIA Tech+ Study Guide identifies RJ45 as the standard Ethernet connector:

“An RJ45 connector is used to connect network cables to devices such as switches, routers, and computers. It’s the most common connector for Ethernet networking.”

RJ45 connectors terminate Cat 5, 5e, and 6 cables for network communication.

Verified Reference:

Chapter 2: Peripherals and Connectors — “Network Connectors: RJ45” (pp. 90–92).