Which option describes 10 Gigabit Ethernet over single-mode fiber with a maximum distance of 10 kilometers?

Which option describes 10 Gigabit Ethernet over single-mode fiber with a maximum distance of 10 kilometers?

• A. Single-Mode Fiber
• B. 1000BASE-LX
• C. Multimode Fiber
• D. 10GBASE-LR

Answer: (D)

10GBASE-LR is the 10 Gigabit Ethernet option designed for long-reach over single-mode fiber. The LR designation means Long Reach, and this standard operates at 10 Gbps over SMF with a typical distance up to about 10 kilometers (using a 1310 nm wavelength). That combination—10 Gbps speed, single-mode fiber, and a 10 km reach—matches the description perfectly. The other options don’t fit because they describe either the fiber type or a different speed. A simple “single-mode fiber” description isn’t a specific Ethernet standard and doesn’t indicate speed or distance. A 1000BASE-LX option is 1 Gbps, not 10 Gbps, and while LX is associated with longer reach, it’s not the 10 Gbps, 10 km SMF answer. Multimode fiber is a type of fiber, not a 10 Gbps single-mode solution.

10GBASE-LR is the 10 Gigabit Ethernet option designed for long-reach over single-mode fiber. The LR designation means Long Reach, and this standard operates at 10 Gbps over SMF with a typical distance up to about 10 kilometers (using a 1310 nm wavelength). That combination—10 Gbps speed, single-mode fiber, and a 10 km reach—matches the description perfectly.

The other options don’t fit because they describe either the fiber type or a different speed. A simple “single-mode fiber” description isn’t a specific Ethernet standard and doesn’t indicate speed or distance. A 1000BASE-LX option is 1 Gbps, not 10 Gbps, and while LX is associated with longer reach, it’s not the 10 Gbps, 10 km SMF answer. Multimode fiber is a type of fiber, not a 10 Gbps single-mode solution.