You are presented with the question "corals use what to communicate with each other" and the following answer choices: 
- Energy
 - pheromones
 - kinetic energy
 - produce light
 - heat produced
 - heat energy
 - Chemical energy
 - sound

Now knowing that echinoderms use pheromones to communicate with each other and ascothoracican barnacles attach to echinoderms or corals, choose the best answer.


 

  pheromones       