Answer :
Gill pouches seems like the most reasonable answer, only because a chordate needs a notochord and a nerve cord.
Answer:
The correct answer would be none of the above.
Explanation:
Chordata has 5 major characteristics that they have at some stage in their lives, a dorsal tubular nerve cord, a notochord, pharyngeal gill slits, a post- tail, and a thyroid/endostyle gland.
The notochord is a flexible, rod-like structure that is present in the development stage of all chordates and reason for the name of the phylum. Nerve cord is rise from the ectoderm and develops into a hollow tube. pharyngeal gill slits let water enter and exit the mouth during feeding.
Thus, the correct answer would be none of the above.