The correct answer is Acephate. Insecticides are substances used to kill insects. Nearly all insecticides have the potential to significantly alter ecosystems, many are toxic to humans and animals. Insecticides can be classified into two major groups:Systemic insecticides: residual or long term activityContact insecticides: no residual activity. Examples: Endosulphan, Fenvalerate, Imidacloprid, Acephate, Carbofuran, Carbaryl.