Answer:
The correct answer is option a. "prodromal".
Explanation:
Prodromal is the first phase of schizophrenia, at which the patient have not experienced an episode of hallucination but started experienced symptoms of changing the way of thinking and started to feel isolated. The description of Iris becoming withdrawn and isolated and her thoughts of a frightening inner world of demons and threats fit with the prodromal phase of schizophrenia. 75% patients go through this phase before starting the active and residual phases of schizophrenia, and it could last from a couple of weeks to several years.