Which transmission medium typically uses an LED light source?

The correct choice is multimode fiber because it is designed to use LED light sources for signal transmission. In multimode fiber optics, the core of the fiber is larger in diameter, which allows multiple light paths or modes to travel through it simultaneously. LED sources are cost-effective and provide sufficient bandwidth for shorter distances, making them ideal for applications such as data centers and local area networks where the transmission distances are limited to a few hundred meters.

Singlemode fiber uses a laser light source, which is focused into a smaller core, allowing only one mode of light to propagate. This configuration is optimal for long-distance transmission, but it is not compatible with LED light sources. Coaxial cable and twisted pair cable are electrical transmission mediums that do not utilize light for data transfer, so they are not applicable in the context of this question regarding light sources.