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: Anatomy
[{'content': 'only nerve that does not have ventral attachment at the base of the brain: \nSelect and explain. \nA. Trochlear, B. Trigeminal, C. Optic, D. Occulomotor', 'role': 'user'}, {'content': 'Answer: A \nExplanation: All cranial nerves have ventral attachments at the base of the brain except trochlear nerve which has dorsal attachment to base of brain.', 'role': 'assistant'}]