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': 'A girl for chronic ear discharge, pain on ocular movements and veigo underwent mastoidectomy. There was no relief post-operatively and continuous purulent ear discharge was seen. Patient also had sensorineural hearing loss. The most probable diagnosis would he: \nSelect and explain. \nA. Suppurative labyrinthitis, B. Apical petrositis, C. Serous labyrinthitis, D. Lateral sinus thrombophlebitis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. b. Apical petrositis', 'role': 'assistant'}]