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: Medicine
[{'content': "During valsalva maneuver, impaired heart rate changes seen in - \nSelect and explain. \nA. Homer's syndrome, B. Autonomic insufficiency, C. Vestibular dysfunction, D. Cephalic ischemia", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]