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': "Edema over the mastoid is seen in - \nSelect and explain. \nA. Bell's Palsy, B. Lateral sinus thrombophlebitis, C. CSOM, D. ASOM", 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is'b'i.e., Lateral sinus thrombophlebitis (Ref: Dhingra sth/e p. 95) Edema over posterior post of mastoid (Griesinger's sign) is seen in lateral sinus thrombosis (signal sinus thrombosis).", 'role': 'assistant'}]