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: ENT
[{'content': "Picket fence fever is a feature of - \nSelect and explain. \nA. Acute mastoiditis, B. Lateral sinus thrombophlebitis, C. Bell's Palsy, D. Atticoantral CSOM", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. Lateral sinus thrombophlebitis Ref: Dhingra Sth/e p. 95] Hectic Picket-Fence fi:pe of fever with rigor,', 'role': 'assistant'}]