fragments that broke off of older rocks. magma that cooled deep below a volcano. gases that condensed in the atmosphere. vegetation that decayed in thick layers.
I gave my students this multiple choice question: Sandstone and all other types of sedimentary rock are made up of particles. The source materials of these particles consist of

Only one answer is correct among these 4 choices:
- fragments that broke off of older rocks.
- magma that cooled deep below a volcano.
- gases that condensed in the atmosphere.
- vegetation that decayed in thick layers.

Could you tell me which one is correct?

fragments that broke off of older rocks.