Fact 1: Organisms cluster around hydrothermal vents in the ocean floor.

Fact 2: Background Hot water vents form inside cracks in the ocean floor.

Given the two facts above, answer the question "What do organisms cluster around, in the ocean floor?" with the following options: 
- cracks
 - chemicals
 - limestone
 - crust
 - headaches
 - Nutrients
 - horses
 - dogs


 

 cracks        