a source of solar power a source of electrical power a source of renewable energy a source of nonrenewable energy
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: It can take millions of years for fossil fuels to form. These fossil fuels form underground from decaying plants and animals. Which term best describes a fossil fuel?
Possibilities:
- a source of solar power
- a source of electrical power
- a source of renewable energy
- a source of nonrenewable energy

a source of nonrenewable energy