Not a synthetic pyrethroid insectiside -

Ans. is 'a' i.e., Propoxuro Inectisides are divided into:-A) Fumigants : Hydrogen cyanide, SO2, methyl bromide, carbon disulphate.B) Stomach poisons: Paris green, Sodium fluoride.C) Contact (nerve) poisons: These are divided into -1) Natural: Pyrethrum, rotenone, Derris, nicotine, mineral oil.2) Synthetic: These are -i) Organophosphates: Malathion, parathion, fenthion, diazinon, fenitrothion, abate, chlorthion, dioxathion, chlorpyrifos, trichlorfon.ii) Carbamates : Carbaryl, propoxur, dimetilan, pyrolon.iii) Organochlorine: DDT, BHC (HCH), dieldrin, aldrin, chlordane, lindane, heptachlor.iv) Synthetic pyrethroid (pyrethrum derivatives) : Pothrin, resmethrin, permethrin, biopermethrin, cypermethrin, cyphenothrin, cycloprothrin, deltamethrin, cyfluthrin, etofenoprox.