a collection of gases held together by inertia a group of planets revolving around a single star a collection of stars and gases with the Sun as its center a group of stars, dust, and planets held together by gravity
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which statement is the best description of the Milky Way galaxy?
Possibilities:
- a collection of gases held together by inertia
- a group of planets revolving around a single star
- a collection of stars and gases with the Sun as its center
- a group of stars, dust, and planets held together by gravity

a group of stars, dust, and planets held together by gravity