A large volume of the solar system's space is occupied by?

The answer is C. Unless u can say hydrogen also since that occupies more space then anything else. But there arnt very many comets in our solarsystem. There are good amount of meteors and on evrything other then the Earth a lot of micrometeoroids. But there are asteroids everywhere ans since there is a huge asteroid belt inbetween mars and jupiter and another even bugger one after pluto the answer is definetly C asteroids.