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: Medicine
[{'content': 'All are true regarding cluster headache except: \nSelect and explain. \nA. Most common in male, B. Periorbital in location, C. Bilateral, D. Symptoms seen in early hours of the morning', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans: C i.e. Bilateral Cluster headache Cluster headache shows a 5:1 predominance of males and onset is usually in the third decade The characteristic presentation of cluster headache is with periodic, severe, unilateral periorbital pain accompanied by unilateral lacrimation, nasal congestion and conjunctival injection, often with other features of Horner's syndrome Typically, the patient develops these symptoms at a paicular time of day (often in the early hours of the morning)", 'role': 'assistant'}]