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: Surgery
[{'content': 'Treatment of a large hydrocele in an infant - \nSelect and explain. \nA. Repeated aspirations, B. Ligation of sac at the opening of ingunal canal, C. Herniotomy, D. Eversion of sac', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]