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 travelling nerve impulse does not depolarize the area immediately behind it, because : \nSelect and explain. \nA. It is hyperpolarized, B. It is refractory, C. It is not self propagating, D. The condition is always ohodromic', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. It is refractory', 'role': 'assistant'}]