A primary care doctor refers a 46- year- old woman with many physical complaints for psychological assessment after extensive medical testing reveals no evidence of physical issues. The psychologists learns that the pt has an extensive hx of bodily complaints without medical basis. Her physical symptoms have been multi systemic and do not resemble the constellation of symptoms associated with specific medical illnesses. The referring doctor also reports that the pt has frustrated many primary care doctors in the past and has transitioned from one to another. The pt expresses her distress to the psychologist. She says, "None of this is in my head. It is real. I have talked to so many doctors and those doctors just can't figure it out. I have no answers, and I feel worse and worse." What is the likely diagnosis?

A. Body dysmorphic disorder.
B. Conversion disorder (functional neurological symptom disorder).
C. Factitious disorder.
D. Somatic symptom disorder.