Which statement best defines a nonselective herbicide?

• A. A substance that kills all plants it contacts
• B. A herbicide that kills only grasses
• C. A chemical that targets soils only
• D. A preemergence herbicide

Answer: (A)

Nonselective herbicides act without distinguishing among plant species; they tend to kill most or all plants they contact. This broad effect is exactly what defines them—used when the goal is to clear an area of vegetation entirely, such as site preparation before planting. In contrast, products that kill only grasses are selective, targeting one group of plants. A chemical that targets soils only isn’t about whether it kills plants on contact; it describes where the action occurs, not the range of plants affected. And a preemergence herbicide refers to timing (applied before weed seeds germinate) rather than whether it will kill multiple plant types.