You are presented with the question "What do organisms cluster around, in the ocean floor?" and the following answer choices: 
- cracks
 - chemicals
 - limestone
 - crust
 - headaches
 - Nutrients
 - horses
 - dogs

Now knowing that organisms cluster around hydrothermal vents in the ocean floor and background Hot water vents form inside cracks in the ocean floor, choose the best answer.


 

 cracks        