only coal. only natural gas. oil and coal. oil and natural gas.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Fossil fuels were made from specific kinds of ancient organisms. The fossilized remains of tiny ocean organisms formed
Possibilities:
- only coal.
- only natural gas.
- oil and coal.
- oil and natural gas.

oil and natural gas.