Correct Answer: A) Hallucinations ✅

Hallucinations are false sensory perceptions without external stimuli. In schizophrenia, auditory hallucinations (hearing voices) are most common and are considered a core symptom for diagnosis.

Excessive worry is typically linked with generalized anxiety disorder and does not indicate schizophrenia.

Delirium is an acute, fluctuating disturbance of consciousness due to medical or metabolic causes, not a primary psychiatric illness like schizophrenia.

Grandiosity is an inflated sense of self-importance, commonly seen in manic episodes of bipolar disorder, not schizophrenia.

👉 Thus, hallucinations are the most reliable symptom that points the nurse toward a diagnosis of schizophrenia.