Which resource is formed over millions of years from decaying biological matter?

The correct answer is C, fossil fuels, because they are indeed formed over millions of years from the decaying remains of ancient plants and animals. This process typically occurs in environments where sediment can accumulate in layers, such as underwater or in swamps. Over time, heat and pressure transform this biological material into coal, oil, and natural gas. This geological timeframe distinguishes fossil fuels from other types of resources, emphasizing their non-renewable nature; they take millions of years to form but can be consumed much more rapidly than they are formed.

Renewable resources, while also crucial, are characterized by their ability to replenish naturally within a human timescale, such as solar energy or timber that can be regrown. Natural resources include a broad array of materials found in nature, encapsulating both renewable and non-renewable resources. Human resources refer to the skills and labor provided by people, which are not created from biological matter. Thus, fossil fuels specifically highlight the transformation of ancient biological matter into energy sources over extensive geological periods.