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: Social & Preventive Medicine
[{'content': 'All of the following methods are anti-larval measures, EXCEPT: \nSelect and explain. \nA. Intermittent irrigation, B. Paris green, C. Gambusia affinis, D. Malathion', 'role': 'user'}, {'content': "Answer: D \nExplanation: Malathion is used primarily for killing adult mosquitoes. It is not recommended as a larvicidal agent Fenthion, Chlorpyrifos and abate are preferred as larvicides. Water management such as intermittent irrigation constitutes a proven method of larval control. Paris green or copper acetoarsenite is a stomach poison and is effective when ingested by the larvae. Gambusia afftnis are small fishes that feed readily an mosquito larvae. Ref: Park's Textbook Of Preventive And Social Medicine By K. Park, 19th Edition, Page 638; Park's Textbook Of Preventive And Social Medicine By K. Park, 18th Edition, Page 570, 579, 590", 'role': 'assistant'}]