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': 'Features of delirium: \nSelect and explain. \nA. Deficit of attention (Attention Deficit), B. Autonomic instability (dysfunction), C. Altered sleep wake pattern, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A. i.e. Deficit of attention; B. i.e. Autonomic instability; C. i.e. Altered sleep wake pattern', 'role': 'assistant'}]