Which of the following best describes a pesticide?

• A. A nutrient added to soil to promote plant growth.
• B. A preservative used to extend the shelf life of food products.
• C. A natural compound produced by plants for photosynthesis.
• D. A chemical substance used to kill or control pests such as insects, weeds, or fungi.

Answer: (D)

Verified step by step guidance

1. Understand the definition of a pesticide: it is a chemical substance used to kill or control pests such as insects, weeds, or fungi.
2. Review each option and compare it to the definition of a pesticide:
3. Option 1 describes a nutrient added to soil, which is related to fertilizers, not pesticides.
4. Option 2 describes a preservative for food, which is unrelated to pest control.
5. Option 3 describes a natural compound for photosynthesis, which is a plant process, not pest control.
6. Conclude that the correct description of a pesticide is a chemical substance used to kill or control pests such as insects, weeds, or fungi.