Answer the following question given this paragraph: 

Some of the most interesting evidence for evolution comes from vestigial structures . These are body parts that are no longer used but are still present in modern organisms. Examples in humans include tail bones and the appendix.


Q: What is the tail bone an example of?

 Choices:

- invertebrate structure

- parasitic structure

- primordial structure

- vestigial structure

A:
vestigial structure
