You are presented with the question "What can change the remains of prehistoric living things into natural gas?" and the following answer choices: 
- rock metamorphizing
 - a hydraulic system
 - Time and energy
 - the ground shaking
 - Temperature
 - one celled organisms
 - chemical reaction
 - flow of electrons

Now knowing that heat and pressure change the remains of prehistoric living things into natural gas and heat and pressure cause a rock to metamorphize, choose the best answer.


 

 rock metamorphizing        