Which energy source is inexhaustible?

• A. Solar
• B. Nuclear
• C. Wind
• D. Coal

Answer: (C)

Inexhaustible energy sources are those that won’t run out because they’re continually replenished by natural processes. Wind energy fits this because wind is air in motion produced by ongoing atmospheric dynamics driven by the sun. When we harvest wind with turbines, we’re not consuming the wind itself; the atmosphere keeps returning wind over and over, so it can supply energy repeatedly on human timescales. That’s why wind is considered inexhaustible. Coal and nuclear rely on finite fuels that can be depleted, while solar energy is also renewable, but this option highlights wind as a clear example of a continuous, flow resource that doesn’t get used up by harvesting.