Answer: Chordates
Explanation:
Pharyngeal slits are found in the embryos of the chordates. Pharyngeal slits are the filter organs present in the chordates. These are the openings in the pharynx near the mouth. The function is to allow the movement of water inside the mouth and the unwanted or excess water is removed by the pharyngeal slits. These slits also aid in respiration of the aquatic chordate animals.