Answer:
B) The object is a moon, not a dwarf planet.
Step-by-step explanation:
The object does not orbit the sun, so it eliminates the possibility that it is a planet or a dwarf planet. (The difference between a planet and a dwarf planet is that the dwarf planet has not yet cleared its orbit.)
It is also mentioned that the object is round, so the object cannot be an asteroid.
Because of the fact that the body it is round and orbits a planet, it is concluded that the object is a moon (also known as satellite) of the planet.