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': 'Right atrial distension leaading to increased heart rate occurs in \nSelect and explain. \nA. Bezold Jarisch reflex, B. Bain bridge reflex, C. J reflex, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]