The correct answer is a sponge.
<span>A sponge (Porifera) is a multicellular organism which consists of two layers of cells and the mesophyll between them. Those cells are unspecialized and can transform into other types. The body of sponges is full of pores and channels which allow the water to circulate and thus to obtain food and oxygen.</span>
<span> myxoamoeba or swarmers </span>
