Using the prefix micro- and using what you know about meteoroids, which description below would best fit?

Hello. This question is incomplete. The full question is:

"Using the prefix micro- and using what you know about meteoroids, which description below would best fit?

A. a large particle of dust or rock moving at slow speeds through space.  B. a small particle of dust or rock moving at fast speeds through space.  C. a large particle of dust or rock moving at fast speeds through space.  D. a small particle of dust or rock moving at slow speeds through space."

B. a small particle of dust or rock moving at fast speeds through space.

Explanation:

Micrometeoroids are small particles of dust or rock, smaller than asteroids, sometimes smaller than an atom, and that roam in space at high speeds. Depending on the diameter of a micrometeoroid, it can reach speeds close to the speed of light.

Micrometeoroids are fragments that have been released from an asteroid or from another rocky celestial body. They are a concern for astronauts who can be reached by them.

i'm pretty sure it's spores