You are presented with the question "What lacks a centralized nervous system?" and the following answer choices: 
- Damaged hearing
 - Pesticides
 - Cats
 - insects
 - Sea urchins
 - barnacles
 - Humans
 - Fish

Now knowing that echinoderms lack a centralized nervous system and starfish and sea urchins are also echinoderms, choose the best answer.


 

     Sea urchins    