What is the definition of a pesticide?

A pesticide is defined as a chemical or substance specifically designed to destroy, prevent, or control pests, which includes a broad range of organisms such as insects, weeds, fungi, and rodents. This definition encompasses a wide variety of products, from insecticides that target harmful insects to herbicides that manage unwanted plants. The purpose of pesticides is fundamentally to protect crops, plants, and sometimes public health by mitigating the effects of these pests.

The other choices do not accurately represent what a pesticide is. For instance, the option describing a chemical to enhance growth refers to fertilizers rather than pesticides, which focus on pest management rather than growth stimulation. Similarly, a substance to feed plants is also a description of fertilizers or soil amendments, not pesticides. Lastly, while natural remedies for weeds may provide some level of control, they do not encompass the full range of chemical pesticides designed for broader pest management. Hence, the selected answer clearly aligns with the established definition of a pesticide and its intended use.