This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
[{'content': "Most common LMN cause of Facial nerve palsy is? \nSelect and explain. \nA. Trauma, B. Bell's palsy, C. Infections, D. Vascular causes", 'role': 'user'}, {'content': "Answer: B \nExplanation: *one of the most common cause of facial weakness is bell's palsy ,a lower motor neuron lesion of the 7th (facial)nerve ,effecting all ages and both sexes *here the lesion is within the facial canal . Ref Harrison20th editionpg 1082-1083", 'role': 'assistant'}]