Explanation:

- Option 1: Fossil Fuel

- Fossil fuels, including coal, oil, and natural gas, remain the largest source of global energy.

- They dominate due to their established infrastructure and energy output.

- Option 2: Nuclear Energy

- Nuclear energy contributes significantly to global electricity but is not the second-largest overall energy source.

- It plays a vital role in providing low-emission power.

- Option 3: Renewable Energy

- Renewable energy, which includes wind, solar, hydroelectric, and biomass, is growing rapidly.

- It is now the second largest source of global energy, driven by global efforts to diversify energy sources and combat climate change.

- Correct Answer

- Option 4: None of these

- This option is incorrect as there are valid choices provided.