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': 'Parasympathetic ganglion in head are \nSelect and explain. \nA. Three pairs, B. Four pairs, C. Five pairs, D. Two pairs', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]