If something caused by pressure differences in the atmosphere is used for producing electricity, then what can be used to produce electricity?

Answer choices:
- Something that generates electricity
 - an automobile engine
 - The bending of a ray of light
 - Something caused by pressure differences
 - that material's properties
 - energy of moving objects
 - series of enzyme-mediated reactions
 - Faulting of rocks in the crust

 

    Something caused by pressure differences      