Herbicides that injure some plants and not others are known as what herbicides?

• A. Broad-Spectrum
• B. Selective
• C. Nonselective
• D. Systemic

Answer: (B)

This item tests selectivity in herbicides—the ability to injure some plants while leaving others unharmed. Selective herbicides exploit differences between species, such as how a weed metabolizes the chemical or how the plant transports or targets it, so they harm the weeds but spare the crop or desired plants. That’s why this type of herbicide fits the description of “injure some plants and not others.”

In contrast, broad-spectrum herbicides kill many species, often including crops, which isn’t what the prompt describes. A nonselective herbicide behaves similarly across species and would not differentiate between crops and weeds. Systemic refers to how the herbicide moves within a plant after uptake, not to the range of species it affects, so it doesn’t define the scenario. Thus, selective herbicides are the correct choice.