Fact 1: Invertebrates are animals that lack a vertebral column, or backbone.

Fact 2: Many invertebrates have an exoskeleton.

Given the two facts above, answer the question "Many animals that lack a vertebral column, or backbone have a what" with the following options: 
- spine
 - exoskeleton
 - parasites
 - Leptospirosis
 - epidermal
 - Damaged hearing
 - skeleton
 - hip bone


 

  exoskeleton       