I think the answer is "the older it is"
Reason: I might be wrong but is something (like a shell) gets buried in something (like sand), overtime many things (like dirt, soil, sand, etc.) will be on top of the original. This will make layers. So, the older rock is on the bottom since it has been there for the longest and it gets covered by other stuff (causing the layers).
Hope this helps! :) (If I'm wrong, sorry :( )
The answer is B. They are both made up of subatomic particles.
Living things in the environment such as plants, animals, and bacteria are biotic factors. Biotic factors also include once-living parts such as dead leaves on the forest floor. Abiotic factors are nonliving aspects of the environment such as sunlight, temperature and water. One important abiotic factor is soil.
