Correct Answer: Hemichordata

Solution : The correct option is Hemichordata.

Balanoglossus belongs to the phylum Hemichordata in the animal kingdom. These marine organisms are a group of deuterostomes, and they share some characteristics with chordates and echinoderms. Balanoglossus, along with other hemichordates, has a structure called a stomochord, which is considered a primitive notochord-like structure.