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: Pathology
[{'content': 'Following is the most important factor in the management of shock: \nSelect and explain. \nA. Blood pressure, B. Cardiac output, C. CVP to 8 cm of water, D. Deficiency of effective circulating blood volume', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]