A user is connecting a router with an SFP connector.

The correct answer is A. Fiber. The typing error “SPF” should be corrected to “SFP,” which stands for small form-factor pluggable. SFP is used with fiber-optic network connections. Ethernet/RJ45 is associated with twisted-pair copper cables. Lightning is an Apple connector, and Thunderbolt is a high-speed peripheral/display interface, not the best match for an SFP router connection.

Exact Extract/Reference: The CompTIA Tech+ Study Guide identifies the “small form-factor pluggable (SFP) connector” as the fiber connector and states, “remember there is RJ45 for twisted-pair copper cables and SFP for fiber-optic cables.”