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
Shock is a circulatory disturbance characterized by: 
Select and explain. 
A. Increased blood, B. Elevated body temperature, C. Increased atmospheric pressure, D. Decreased volume of circulating blood
D: Decreased volume of circulating blood
Answer: D: Decreased volume of circulating blood 
Explanation: None