Answer:
I would go with B
Explanation:
first of all,planets don´t exist in Kuiper belt because that is where dwarfs go
second,a planet is not a moon of another object,there is no such thing as that
third,planets do have enough gravity to keep other objects far away from its orbit.
fourth,a planet does orbit around the sun
fifth,planets do have a long orbit
sixth,a planet is also almost in a circular shape
B was the most likely to be a planet because one of the characteristics were wrong,unlike the others,I also hope this helps and hope that its the right answer,I'm actually not too sure,sorry if I got it wrong.