This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
[{'content': 'A young boy of 18 years gets recurrent busts of otitis externa after swimming. Which of the following methods should be recommended? \nSelect and explain. \nA. Not to swim, B. Use 2% acetic acid after swimming, C. Use ear drops containing an antibiotic and steroid, D. Use an antifungal ear drops after swimming', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Use of 2% acetic acid or dilute alcohol is the most-effective method to prevent otitis externa after swimming. Antibiotic, antifungal or steroid containing drugs are not recommended for prophylaxis.', 'role': 'assistant'}]