This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brainstem, cerebellum and ventricles, Subject name: Anatomy
[{'content': 'Which one of the cranial nerves exits the brainstem from the posterior aspect? \nSelect and explain. \nA. CN I, B. CN II, C. CN III, D. CN IV', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Trochlear nerve (CN IV)is the only cranial nerve to exit the brainstem from the dorsal/ posterior aspect.', 'role': 'assistant'}]