A primary care physician refers a 60- year- old Cambodian man to a psychiatrist to rule out a psychotic disorder. The man was previously given a diagnosis of Schizophrenia b/c he "hears voices". He has been prescribed a large dose of an antipsychotic medication, which he talked daily, with very little symptom relief. He states that the medicine helps him sleep. The psychiatrist learns that the man is a survivor of the Cambodian genocide of the 1970s who survived torture under the Khmer Rouge regime, witnessed executions, and endured forced labor in Communist Cambodia. The man reports that subsequent to the extremes of traumatic experience he sustained, he has had chronic symptoms of anxiety with panic attacks. He also reports a concern of "thinking too much". When asked to clarify what he means, he describes ruminating, worried thoughts about his past traumas. He reports severe insomnia and nightmares about Cambodia at night. He describes hearing voices other people do not hear. Further questioning reveals that the voices he hears are of Khmer Rouge officers, and he "hears" them when he is remembering his experiences of violence. When the psychiatrist asks him to clarify this, he says the "voices" are more like memories than hallucinations. What is the likely diagnosis?

A. Bipolar I disorder, current episode manic.
B. Panic disorder.
C. Posttraumatic stress disorder.
D. Schizophrenia.