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': 'External auditory canal exostosis occurs due to? \nSelect and explain. \nA. Repeated instrumentation, B. Recurrent otitis externa, C. Wide external auditor meatus, D. Recurrent proplonged cold water exposure', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Recurrent proplonged cold water exposure Ear canal exostoses are bilateral, usually symmetric multiple bony growths occurring in the medial poion of the external auditory canal. Also known as surfer's ear, exostosis is thought to be a reactive process from repeated stimulation by cold water and is much more common than external auditory osteoma", 'role': 'assistant'}]