A College Student Observes a Roommate Going Out Wearing Uncharacteristically

A college student observes a roommate going out wearing uncharacteristically seductive clothing, returning 12 to 24 hours later, and then sleeping for 8 to 12 hours. At other times, the roommate sits on the floor speaking like a young child. Which health problem should be considered?

A) Functional neurological (conversion) disorder
B) Dissociative identity disorder
C) Dissociative amnesia
D) Derealization disorder