To determine which term does NOT belong under the heading "Natural Resource," we need to look at the definitions of each option:
A. Gas - This is a natural resource that can be considered nonrenewable (like fossil fuels).
B. Trees - This is a natural resource that is usually categorized as renewable since they can grow back.
C. Copper - This is a natural resource that is considered nonrenewable as it is a metal mined from the earth.
D. Electricity - While electricity is energy, it is not a natural resource in itself. It is generated using other resources like coal, wind, or water.
Based on this reasoning, the term that does NOT belong under the heading "Natural Resource" is:
D. electricity.