Fact 1: Echinoderms lack a centralized nervous system.

Fact 2: Echinoderms are represented by the starfish.

Given the two facts above, answer the question "What is something missing in starfish?" with the following options: 
- the body's largest organ
 - centralized nervous system
 - characteristics
 - layers of fat
 - permineralization
 - biological diversity
 - kinetic energy
 - A compound that donates proton


 

  centralized nervous system       