What is the primary feature of the Kuiper Belt?

The Kuiper Belt is primarily known for being a region of the solar system located beyond the orbit of Neptune, filled with numerous icy bodies and small celestial objects. This area is a significant part of our solar system's structure, featuring many objects composed mainly of ice, such as water, ammonia, and methane, in addition to rock.

This region is home to a variety of small bodies including dwarf planets like Pluto, Haumea, and Makemake, which are remnants from the early solar system. The presence of these icy objects is a defining characteristic of the Kuiper Belt, making it distinct from other areas of the solar system, such as the dense star regions found in the Milky Way or the rocky asteroids located in the inner solar system.

Although some options present interesting facts about different regions or features, they do not accurately encapsulate the defining quality of the Kuiper Belt, which is predominantly characterized by icy objects.