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: Surgery
[{'content': 'Shock is a circulatory disturbance characterized by: \nSelect and explain. \nA. Increased blood, B. Elevated body temperature, C. Increased atmospheric pressure, D. Decreased volume of circulating blood', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]