This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brainstem lesions and blood supply of CNS, Subject name: Anatomy
[{'content': 'Which nucleus is present under the facial colliculus ? \nSelect and explain. \nA. 7th nucleus, B. 6th nucleus, C. 5th nucleus, D. 10 th nucleus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Facial nerve nucleus sends axons winding around 6th nucleus produces rounded elevation in superior pa of floor of fouh ventricle called facial colliculus. Injury to facial Colliculus leads to paralysis of Risorius muscle supplied by facial nerve.', 'role': 'assistant'}]