Final answer:
Plant growth regulators do not fall under the category of pesticides according to the EPA. Pesticides are intended for pest control and include many types, but growth regulators are meant to influence plant processes. Options such as herbicides, fungicides, and miticides are indeed pesticides.
Step-by-step explanation:
Among the options provided, d. plant growth regulator is not a pesticide according to the Environmental Protection Agency (EPA). Pesticides are substances or mixtures of substances intended for preventing, destroying, repelling, or mitigating any pest. Common types of pesticides include herbicides, insecticides, fungicides, rodenticides, and nematicides. In contrast, plant growth regulators are substances that influence plant processes such as flowering, root development, and fruit ripening.
The pesticide DDT is an example of a chemical agent, and from the perspective of human health, malnutrition is important because it is an important contributor to child mortality. In ecosystems, plant resistance to chemicals serves a similar role to pesticides by providing defense against pests.