Nematocysts Are

Nematocysts are

A) widespread among the animal kingdom but first developed by Cnidaria.
B) formed and used only by Cnidaria although a few other organisms may "steal" them.
C) first found in sponges,most highly developed in cnidarians,but still found as remnants in some higher groups.
D) actually free-living symbionts that are most usually taken up by cnidarians,as are many green algae.
E) None of the choices is correct