Causes of delirium include all of the following except:

Rationale: A. Prescription drugs, untreated pain is incorrect because certain medications (e.g., sedatives, opioids, anticholinergics) and untreated pain are well-known contributors to delirium. These factors can affect neurotransmitter balance and precipitate acute cognitive changes. B. Dehydration, dementia, stress, infection is incorrect because fluid and electrolyte imbalances, pre-existing cognitive impairment, physiologic stress, and infections are all common triggers for delirium, particularly in older adults or critically ill patients. C. Unfamiliar environment is incorrect because environmental changes, sensory overload or deprivation, and disorientation can precipitate delirium, especially in hospitalized or ICU patients. D. Over-the-counter medications, stable environment, no change in health status is correct because in the absence of physiological or pharmacological stressors, delirium is unlikely to occur. A stable environment and no changes in health status do not contribute to delirium, and typical over-the-counter medications taken safely rarely induce acute cognitive changes.