Radioactive isotopes emit high-energy particles that can damage dna. these substances are known as

Mutagens are high energy particles that can damage DNA which are emitted by radioactive isotopes. These are substance that serves as a chemical or physical agent, such as radiation or a chemical substance, which causes genetic mutation or that changes the genetic material.

I think the correct answer from the choices listed above is option D, none of the choices. Sunlight driving photosynthesis in plants, herbivores feeding on plants  and predators feeding on herbivores are all examples of energy transformations in an ecosystem.