You are presented with the question "What can cause chemical weathering?" and the following answer choices: 
- Calcium carbonate
 - our nearest star
 - global warming
 - sea squirts
 - swamp vegetation
 - single-celled organisms
 - flowerless plants
 - Earthworms

Now knowing that moss causes chemical weathering and mosses Mosses are flowerless plants that grow in clumps, choose the best answer.


 

       flowerless plants  