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': 'Pulsatile otorrhoea is seen in - \nSelect and explain. \nA. Glomus tumor, B. CSF otorrhea, C. ASOM, D. Fistula', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]