You are presented with the quiz "marine and benthic species use pheromones to what?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "echinoderms use pheromones to communicate with each other" and "all echinoderms are marine and benthic". 

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


 

       communicate with each other    