A 26-year-old male with schizophrenia presents with poverty of speech, flat affect, and avolition. Which of the following symptoms, if present, would classify as a positive symptom rather than a negative one?

Correct option is C

Positive symptoms are those that add abnormal experiences (hallucinations, delusions). Negative symptoms reflect loss of normal functions (alogia, avolition, flat affect). Delusion is therefore a positive symptom.
Explanation of options: (a) ✘ Anhedonia = inability to feel pleasure, a core negative symptom. (b) ✘ Ambivalence = contradictory emotions, also negative. (c) ✔ Correct; delusion of persecution is a positive symptom. (d) ✘ Avolition = lack of motivation, a negative symptom.