Concept:A natural resource is any material or form of energy found naturally in the environment and useful to people.
Explanation:Wildlife exists naturally in forests and is a natural resource.
Solar energy comes directly from the sun, so it is a natural resource.
Gold is a mineral resource obtained from the earth, so it is a natural resource.
An iron rod, however, is a manufactured item made by processing iron ore.
Although iron ore is natural, turning it into a rod requires human effort and industry.
Therefore, an iron rod is not a natural resource.
Answer:A. iron rod