Fact 1: Vertebrates are all chordates that have a backbone.

Fact 2: Fish are the first known true chordates.

Given the two facts above, answer the question "What was the first known animal with a backbone?" with the following options: 
- pigs
 - Birds
 - sharks
 - Elephant
 - Dog
 - Fish
 - Human
 - Man


 

      Fish   