coal and natural gas natural gas and nuclear energy nuclear energy and hydropower hydropower and coal
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Most electricity in the United States is generated using coal, natural gas, nuclear energy, or hydropower. Which of these add carbon dioxide to the atmosphere?
Possibilities:
- coal and natural gas
- natural gas and nuclear energy
- nuclear energy and hydropower
- hydropower and coal

coal and natural gas