This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
[{'content': 'Which of the following is not helpful in preventing dracunculiasis? \nSelect and explain. \nA. Filtering of drinking water, B. Active search for new cases, C. Mass mebendazole treatment, D. Education regarding water hygiene', 'role': 'user'}, {'content': 'Answer: C \nExplanation: No drug is suitable for effective mass treatment. However infected persons are treated with niridazole, mebendazole or metronidazole.', 'role': 'assistant'}]