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': 'Not a synthetic pyrethroid insectiside \nSelect and explain. \nA. Propoxur, B. Permethrin, C. Cypermethrin, D. Etofenoprox', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., PropoxurInectisides are divided into :Fumigants : Hydrogen cyanide, SO2, methyl bromide, carbon disulphate.Stomach poisons : Paris green, Sodium fluoride.Contact (nerve) poisons : These are divided into Natural : Pyrethrum, rotenone, Derris, nicotine, mineral oil.Synthetic : These are -Organophosphates : Malathion, parathion, fenthion, diazinon, fenitrothion, abate, chlohion, dioxathion, chlorpyrifos, trichlorfon.Carbamates : Carbaryl, propoxur, dimetilan, pyrolon.Organochlorine : DDT, BHC (HCH), dieldrin, aldrin, chlordane, lindane, heptachlor.Synthetic pyrethroid (pyrethrum derivatives) : Pothrin, resmethrin, permethrin, biopermethrin, cypermethrin, cyphenothrin, cycloprothrin, deltamethrin, cyfluthrin, etofenoprox", 'role': 'assistant'}]