Balanoglossus is a member of which phylum?

The correct answer is Hemichordata

Explanation:

• Hemichordata is a small phylum of marine deuterostome animals, generally considered the sister group of the echinoderms.
• Hemichordata consists of a small group of worm-like marine animals with the organ-system level of organisation.
• They are bilaterally symmetrical, triploblastic and coelomate animals.
• The body is cylindrical and is composed of an anterior proboscis, a collar and a long trunk.
• Examples of Hemichordata are Balanoglossus and Saccoglossus.

Other Options:

• Arthropoda: This is the largest phylum in the animal kingdom, including insects, arachnids, and crustaceans. They have segmented bodies, exoskeletons, and jointed appendages. Examples are Apis (Honey bee), Bombyx (Silkworm), Laccifer (Lac insect), Anopheles, Culex and Aedes (Mosquitoes) Locusta (Locust), living fossil – Limulus (King crab).
• Mollusca: This phylum includes soft-bodied animals, many of which have hard external shells, such as snails, clams, and squids. Mollusks have a distinct body plan that includes a muscular foot, visceral mass, and mantle. Examples are Pila. 
• Coelenterata (Cnidaria): This phylum comprises aquatic animals like jellyfish, corals, and sea anemones. They are characterized by their radial symmetry, a simple body plan with a single opening, and specialized stinging cells called cnidocytes. Examples are Obelia, Aurelia