Michelle is observing a sand sample under a microscope when she finds many perforated shelled organisms. Further testing reveals that these shells are made of calcium carbonate. How should she classify these organisms?

A. They are sarcodines, belonging to phylum heliozoa of protozoa.
B. They are radiolarians, belonging to phylum ciliata of protozoa.
C. They are foraminiferans, belonging to phylum sarcodina of protozoa.