Solution

Hemichordates are enterocoelous coelomates with radial cleavage.
Enterocoelic coelom (enterocoel) develops as mesodermal pouches, arising from the gut of the embryo.
Pseudocoelom is the false body cavity that lies between the body wall and the gut. Nematodes have pseudocoelom.
Schizocoelous refers to the condition of embryonic development in which the body cavity is formed by the splitting of the mesoderm.

So, the correct answer is option A.