Select the vertebrate.

 - brown pelican
 - fly
 - banana slug
 - redback spider
Like other spiders, a redback spider is an invertebrate. It does not have a backbone. It has an exoskeleton.
A fly is an insect. Like other insects, a fly is an invertebrate. It does not have a backbone. It has an exoskeleton.
A brown pelican is a bird. Like other birds, a brown pelican is a vertebrate. It has a backbone.
Like other slugs, a banana slug is an invertebrate. It does not have a backbone. It has a soft body.