This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
[{'content': 'Longest cranial nerve is \nSelect and explain. \nA. Vagus, B. Trigeminal, C. Trochlear, D. Olfactory', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The word "vagus" means wandering in Latin. This is a very appropriate name, as the vagus nerve is the longest cranial nerve. It runs all the way from the brain stem to pa of the colon. Ref - medscape.com', 'role': 'assistant'}]