The Following Questions Refer to the Paragraph Below

The following questions refer to the paragraph below.
An elementary school science teacher decided to liven up the classroom with a salt-water aquarium. Knowing that salt-water aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several gastropod varieties. Lastly, some vertebrates-a parrotfish and a clownfish-were added. She arranged for daily feedings of copepods and feeder fish.
-The clownfish and parrotfish died on the same day. Autopsies revealed the presence of many small, flat worms using tiny suckers to attach to the fish gills. Most likely, these worms were members of which phylum, and which class?

A) Annelida, Hirudinea
B) Annelida, Polychaetae
C) Platyhelminthes, Cestoda
D) Platyhelminthes, Monogenea
E) Platyhelminthes, Turbellaria