Answer:
c) The planetoid is being attracted toward another massive object.
Explanation:
We can rule out a, the planetoid is travelling through space, friction is effectively nonexistent. B can be ruled out as well, as there is nothing in space that could naturally repel a planetoid. D is also implausible, as the question says the planetoid slows down for a certain period in its orbit, suggesting this behavior is repeated. Option c is incredibly likely, as the planetoid is far from the sun, a large mass, possibly far smaller than the sun but also far closer to the planetoid, could have the effect described in the question.
It means similarities between two or more things... Is that what you were looking for?