You are presented with the question "What do echinoids lack?" and the following answer choices: 
- characteristics
 - centralized nervous system
 - permineralization
 - the body's largest organ
 - biological diversity
 - that material's properties
 - aerobic capacity
 - organic matter

Now knowing that echinoderms lack a centralized nervous system and another group of echinoderms are the echinoids, choose the best answer.


 

  centralized nervous system       