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: Unknown
[{'content': 'A sudden increase in total peripheral resistance has all of the following effect except: \nSelect and explain. \nA. Increase the diastolic blood pressure, B. Reduce the stroke volume, C. Increase the mean arterial blood pressure, D. Increase cardiac output', 'role': 'user'}, {'content': 'Answer: D \nExplanation: An increase in total peripheral resistance leads to an increase in mean arterial blood pressure (Mean arterial blood pressure = Cardiac output x Total peripheral resistance). Mean arterial blood pressure is a good measure of afterload, which is a measure of the force the heart must develop during ejection. An increase in total peripheral resistance therefore increases afterload. A sudden increase in total peripheral resist\xadance momentarily reduces stroke volume and, there\xadfore, cardiac output. The reduced ejection leads to an increase in end-systolic volume and a subsequent increase in end-diastolic volume. In the long term, stroke volume is maintained because the left ventricle now develops a greater force of contraction (ventricular systolic pressure increases) and cardiac output returns to normal.', 'role': 'assistant'}]