Chordates have a complete digestive system and a closed circulatory system, and all chordates are vertebrates. Given these facts, what do all vertebrates have among the following options:
- sensory neurons
 - characteristics
 - a complete digestive system
 - Veins and arteries.
 - sub-units of species
 - wings and feathers
 - gills
 - gizzard


 

   a complete digestive system      