CompTIA Network+ Practice Test

Single-mode fiber is designed for long-range communication, making it capable of transmitting data across distances of up to 100 kilometers (km) or more without signal degradation. This capability stems from its small core diameter (about 8 to 10 micrometers), which allows light to travel in a straight line down the fiber, minimizing modal dispersion. This means that for applications that require high bandwidth and long distances, single-mode fiber is the preferred choice.

In contrast, options referring to orange coloring and inexpensive light sources like LEDs are characteristic of multimode fiber, which is better suited for shorter distances, typically up to 2 km. Thus, single-mode fiber's unique design and specifications support its significant range advantages, making it the correct choice for this question.