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': 'AV nodal delay is \nSelect and explain. \nA. 0.2 sec, B. 0.13 sec, C. 0.01 sec, D. 0.3 sec', 'role': 'user'}, {'content': 'Answer: B \nExplanation: AV nodal delay- 0.10 to 0.13 sec', 'role': 'assistant'}]