Question

a dwarf planet is a
small, rocky object that orbits the sun and is usually found in a belt between the orbits of mars and jupiter
small object made of ice and dust that orbits the sun and forms a coma as it approaches the sun
round object that orbits the sun but lacks the ability to clear the neighborhood around its orbit
meteoroid that burns up in earths atmosphere, producing a streak of light

Explanation:

A dwarf planet is defined as a round object that orbits the Sun but lacks the ability to clear the neighborhood around its orbit. The first option describes an asteroid, the second describes a comet, and the fourth describes a meteor.

Answer:

round object that orbits the Sun but lacks the ability to clear the neighborhood around its orbit