In a Biology Lab Dissection,you Find That an Organism,called a Lancelet,has

In a biology lab dissection,you find that an organism,called a lancelet,has a flexible rod of nerve cells,extending along its back to its tail.It is a member of the phylum

A) Echinoderms.
B) Arthropods.
C) Nematodes.
D) Chordates.
E) Cnidarians.