The correct option is
D all of the above
An insecticide is a substance used to kill insects. Weedicides are pesticides that are used to kill weeds. Rodenticides are pesticides that kill rodents. Rodents include not only rats and mice, but also squirrels, woodchucks, chipmunks, porcupines, nutria and beavers. DDT can be used as all of these. The structure of DDT is as given above.