"If All the Matter in the Universe Except the Were

"If all the matter in the universe except the were swept away,our world would still be dimly recognizable,and if,as disembodied spirits,we could then investigate it,we should find its mountains,hills,vales,rivers,lakes,and oceans represented by a film of.The location of towns would be decipherable,since for every massing of human beings there would be a corresponding massing of certain.Trees would still stand in ghostly rows representing our streets and highways.The location of the various plants and animals would still be decipherable,and,had we sufficient knowledge,in many cases even their species could be determined by an examination of their erstwhile parasites." The missing term in this passage is

A) flatworms.
B) bacteria.
C) nematodes.
D) rotifers.
E) protozoans.