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

Fact 2: Animals at underwater hydrothermal vents are unique.

Given the two facts above, answer the question "What are organisms on the ocean floor?" with the following options: 
- conventional
 - common
 - unique
 - protected
 - parasites
 - tortoises
 - normal
 - bacteria


 

   unique      