Which statement best describes a renewable resource?

• A. A resource that cannot be replaced.
• B. A resource that is only available in certain regions.
• C. A resource that has a theoretically unlimited supply and is not depleted when used by humans.
• D. A resource that is expensive to extract.

Answer: (C)

Renewable resources are those that can be replenished naturally over time. The statement that best describes them is that they have a theoretically unlimited supply and are not depleted when used by humans. This captures the idea that sources like sunlight, wind, and moving water can be harnessed repeatedly without running out on human time scales, because they continuously exist or are continually regenerated. In contrast, nonrenewable resources form or accumulate far more slowly than we use them, so they can be exhausted.

The other descriptions miss the defining feature: a resource that cannot be replaced points to nonrenewables; being available only in certain regions speaks to geographic distribution rather than renewability; and being expensive to extract concerns cost, not whether the resource replenishes itself.