You are presented with the quiz "Organisms cluster around formations in the ocean floor powered by the heat of submarine what" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "organisms cluster around hydrothermal vents in the ocean floor" and "hydrothermal vents are powered by the heat of submarine volcanoes". 

So, what's the best answer to the question?


 

  volcanoes         