The nurse suspects a client is experiencing delirium. Which specific assessment information would support this suspicion?

A. Onset is insidious (gradual) and relentless: Gradual, progressive onset is more typical of neurocognitive disorders such as dementia. Delirium usually develops rapidly rather than slowly. B. Symptoms last for 1 month or longer: Delirium is generally acute and short-term, often lasting hours to days, although it may persist longer if the underlying cause is not addressed. Prolonged symptoms suggest other cognitive disorders. C. Slow onset of confusion and agitation: A slow, progressive onset is more characteristic of chronic cognitive decline, not the sudden changes seen in delirium. Agitation in delirium typically appears abruptly alongside fluctuating cognition. D. A decreased level of consciousness with intermittent hypervigilance: Fluctuating levels of consciousness, ranging from drowsiness to hyperalertness, are hallmark features of delirium. This variability distinguishes delirium from other cognitive disorders and supports the suspicion of an acute confusional state.