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': 'Pressure on carotid sinus cause: \nSelect and explain. \nA. Hyperapnea, B. Reflex bradycardia, C. Tachycardi, D. Dyspnea', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Reflex bradycardia', 'role': 'assistant'}]