Which one of the following statements regarding coelom of given animals is correct?

Acoelomates are the animals with solid body plan, and lack a body cavity. E.g., poriferans, coelenterates, ctenophores, flatworms, etc.

Pseudocoelomates are animals that have false or pseudocoelom. E.g., Aschelminthes. 

Coelomates are animals that have true coelom enclosed by mesoderm on both sides. E.g., Annelida to Arthropoda.