Answer the following question given this paragraph: 

Later, a true coelom evolved. This is a fluid-filled body cavity that is completely enclosed by mesoderm. The coelom lies between the digestive cavity and body wall. You can see it in the invertebrate in Figure below . Modern invertebrates with a coelom include mollusks (Phylum Mollusca) and annelids (Phylum Annelida).


Q: What is a fluid-filled body cavity that is completely enclosed by mesoderm called?


A:
coelom