What term describes a pesticide that controls some related pests but not others (for example, grasses but not broadleaves)?

• A. Non-Selective Pesticides
• B. Systemic Pesticides
• C. Contact Herbicides
• D. Selective Pesticides

Answer: (D)

Selective action describes a pesticide's ability to control certain pests while sparing others. In the example, the herbicide targets grasses but not broadleaf plants, so it’s designed to affect a specific group of weeds. That focused effect is what makes it selective. Non-selective products kill a broad range of organisms, so they wouldn’t fit this scenario. Systemic describes how the chemical moves inside a plant, and contact describes whether it must touch tissue to work, neither of which define the scope of pest targets. So the term that best describes this behavior is selective pesticides.