You are presented with the question "Something in the polyp stage can form large colonies in shallow tropical what?" and the following answer choices: 
- mountains
 - ice
 - porous
 - CO 2
 - complex
 - colonies
 - wetland
 - water

Now knowing that corals form large colonies in shallow tropical water and corals Corals are in the polyp stage, choose the best answer.


 

        water 