nuclear fuel. biogas. coal gas. diesel fuel.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: In 1995, a private bus company in Washington, D.C., introduced a program to run all its tour buses with fuel obtained from soybeans. The buses are powered by
Possibilities:
- nuclear fuel.
- biogas.
- coal gas.
- diesel fuel.

biogas.