The larva of 'tongue worm' is known as
Veliger is the term used for the larva of gastropods and bivalves.
Tornaria is the larva of some hemichordate species.
Echinopluteus is the larva of some species belonging to the group Echinoidea.
Trochophore larvae are commonly found in annelids and some groups of mollusks.
Tongue worms belong to the group of parasitic crustaceans called Pentastomida. They are basically in the subphylum Crustacea. They are also assumed to be the connecting links between annelids and arthropods. They have arthropod-like larvae.
So, the correct answer is 'None of the above'.