An RN at an Elementary School Notices a Second Grade

An RN at an elementary school notices a second grade female scratching and pulling at her pants. The student complains that her buttocks itch. Upon further assessment, the patient reports that the itching worsened in the morning hours. Since another child in the student's class was recently diagnosed with Enterobius vermicularis, or pinworm infection, the RN. contacts the girl's mother and recommends follow up with her pediatrician.
-Pinworm is characterized as which type of helminth?  

A) Nematode
B) Flatworm
C) Trematode
D) Cestode