This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brain , Subject name: Anatomy
[{'content': 'All the following nuclei are seen on the floor of fouh ventricle except \nSelect and explain. \nA. Facial nucleus, B. Dorsal vagal nuclei, C. Hypoglossal nucleus, D. Abducens nucleus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Facial nuclei are not seen on the floor of fouh ventricle. Cranial nerve nuclei underneath the floor of 4the ventricle are: Abducent nucleus Vestibular nuclei Hypoglossal nucleus Dorsal nucleus of Vagus Nuclei of 9 and 11 cranial nerves (Ref: Vishram Singh textbook of clinical neuroanatomy, second edition pg 122, also refer table 10.3)', 'role': 'assistant'}]