I think the correct answer from the choices listed above is the first option. Vertebrates are a subphylum to the Chordata phylum. The phylum Chordata contains all animals that possess, at some point during their lives, a hollow nerve cord and a notochord, a flexible rod between the nerve cord and the digestive track.
Vertebrates are a subphylum to the Chordata phylum.
Explanation:
The phylum Chordata contains all animals that possess, at some point during their lives, a hollow nerve cord and a notochord, a flexible rod between the nerve cord and the digestive tract.
