Fact 1: Echinoderms use pheromones to communicate with each other.

Fact 2: Scent marks contain molecules called pheromones.

Given the two facts above, answer the question "What do echinoderms use to communicate?" with the following options: 
- vision
 - words
 - sound
 - Light
 - waves
 - Acids
 - language
 - scent


 

        scent 