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: Pathology
[{'content': "Alarm clock headache is a feature of: \nSelect and explain. \nA. Trigeminal neuralgia., B. Sphenopalatine neuralgia, C. Horner's syndrome., D. Glossopharyngeal neuralgia", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]