Roundworms may be free-living or parasitic.
Roundworms make up the roundworm phylum, nematoda.
The phylum nematoda can be parasitic.
What can the phylum Nematoda be?
(A) dangerous
(B) parasitic
(C) horses
(D) meiosis
(E) more abundant
(F) graptolites
(G) homogenous
(H) phytoplankton