You are presented with the question "What is something missing in starfish?" and the following answer choices: 
- the body's largest organ
 - centralized nervous system
 - characteristics
 - layers of fat
 - permineralization
 - biological diversity
 - kinetic energy
 - A compound that donates proton

Now knowing that echinoderms lack a centralized nervous system and echinoderms are represented by the starfish, choose the best answer.


 

  centralized nervous system       