The Sun turned diatoms into oil after 10-20 years. Diatoms are the original source of energy for oil. The Sun is the original source of energy for oil. Diatoms converted oil into energy.
I gave my students this multiple choice question: The oil used today is made from the ancient remains of tiny sea creatures called "Diatoms." When they were alive, the Diatoms converted sunlight into stored energy. Based on this information, which of the following statements is true?

Only one answer is correct among these 4 choices:
- The Sun turned diatoms into oil after 10-20 years.
- Diatoms are the original source of energy for oil.
- The Sun is the original source of energy for oil.
- Diatoms converted oil into energy.

Could you tell me which one is correct?

The Sun is the original source of energy for oil.