coal, oil, and natural gas solar, oil, and geothermal wind, solar, and tidal natural gas, solar, and tidal
I gave my students this multiple choice question: Which group of energy sources are ALL renewable?

Only one answer is correct among these 4 choices:
- coal, oil, and natural gas
- solar, oil, and geothermal
- wind, solar, and tidal
- natural gas, solar, and tidal

Could you tell me which one is correct?

wind, solar, and tidal