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': 'A hormone involved in regulation of BP - \nSelect and explain. \nA. Serotonin, B. Angiotensin- II, C. Dopamine, D. Prostaglandin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Compensatory mechanisms in acute haemorrhage\n\nIn acute haemorrhage there is compensatory sympathetic stimulation which causes\n\n1) Generalized vasoconstriction with increased total peripheral resistance (TFR).\n2) Increased heart rate (tachycardia).\n3. Increased cardiac contractility.\n4. Increased renin release causing sodium and water retention through the RAA system.\n5. The shift of fluid from intracellular and interstitial space into vascular space.', 'role': 'assistant'}]