What is a pesticide?

A pesticide is defined as a substance specifically designed to kill or control harmful organisms, including pests that can damage crops, spread diseases, or pose threats to human health. This definition encompasses a wide variety of chemical products used in agricultural, residential, and public health contexts.

In this context, the correct answer identifies the primary function of pesticides, which is to eliminate or deter organisms that are deemed undesirable or harmful. Pesticides can be chemical or biological in nature and are commonly utilized in various applications to enhance food production, safeguard structures from infestations, and protect public health.

The other options represent different pest management methods, such as mechanical traps, which physically capture pests, cultural practices that utilize environmental management strategies to deter pests, and biological controls which employ natural predators or pathogens to manage pest populations. While all these methods are important components of pest management, they do not fit the specific definition of a pesticide as a substance meant to kill harmful organisms directly.