Fact 1: Echinoderms lack a centralized nervous system.

Fact 2: Another group of echinoderms are the echinoids.

Given the two facts above, answer the question "What do echinoids lack?" with the following options: 
- characteristics
 - centralized nervous system
 - permineralization
 - the body's largest organ
 - biological diversity
 - that material's properties
 - aerobic capacity
 - organic matter


 

  centralized nervous system       