All of the following invertebrate groups have tissues except ... A. Annelids B. Exhinoderms C. Molluses D. Sponges

Sponges doesn't have tissues in them.

Explanation:

Porifera are the most simple organisms of all the invertebraes and they do not represent tissue level organization in them.Sponges evolved much earlier than any other animals and are embryologically homologous to those of all other derived animal groups such as the insects and mammals. So they don't have true tissue.Sponges don't possess true tissue system also they don't have internal organs, muscles, nervous system and circullatory system.Instead their walls are filled with many minute orifices called ostia that enable water flow into the sponge.Sponge larvae can swim whereas the grown-ups are fixed and settle their life connected to a substratum.