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: Physiology
[{'content': 'Which of the following organ is spared from vasoconstriction during hypovolemic shock? \nSelect and explain. \nA. Skin, B. Hea, C. Kidney, D. Liver', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In severe hypovolemic shock, tachycardia is replaced by bradycardia. Vasoconstriction is generalized, sparing only the vessels of the brain and hea. This widespread reflex vasoconstriction also helps in maintain the filling pressure of the hea. Ref: Ganong Review Of Medical Physiology By Barrett, 2010, Page 516.', 'role': 'assistant'}]