Select the option which shows the correct combination of an organism and its feature.
Balanoglossus is a hemichordate. In hemichordates, body is divided into a proboscis, collar and a long trunk.
Echinus is an echinoderm. Special excretory organs are absent in echinoderms.
Dentalium is a mollusc. Molluscs are unsegmented.
Fertilization is mostly internal in arthropods (e.g., Bombyx), except a few aquatic forms.