This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
[{'content': 'Delirium is defined as ? \nSelect and explain. \nA. Acute onset of disturbed consciousness, B. Chronic onset of disturbed consciousness, C. Progressive generalized impairment of intellectual functions and memory without impairment of consciousness, D. Disorientation without clouding of consciousness', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. Acute onset of disturbed consciousnessDelirium is defined by the acute onset of fluctuating cognitive impairment and a disturbance of consciousness.It is also referred to as acute confusional state or acute organic brain syndrome.', 'role': 'assistant'}]