You are presented with the question "What may be stored in limestone for millions of years?" and the following answer choices: 
- dark matter
 - chemicals
 - still-living organisms
 - nothing
 - fossils
 - matter
 - carbon
 - Energy

Now knowing that carbon may be stored in sedimentary rock for millions of years and limestones are a common type of sedimentary rock, choose the best answer.


 

       carbon  