Which statement best describes a biological control agent?

• A. A living organism used to control pest populations
• B. A chemical pesticide
• C. A mechanical trap
• D. A genetic modification technique

Answer: (A)

A living organism used to reduce pest populations describes a biological control agent. This approach relies on natural interactions like predation, parasitism, or disease to lower pest numbers, such as lady beetles eating aphids or parasitic wasps attacking caterpillars. In contrast, a chemical pesticide is a manufactured chemical, a mechanical trap is a device, and a genetic modification technique is a method to alter organisms—none of which are living organisms used to directly control pests.