Q: You are presented with the quiz "What can be used to produce electricity?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "wind is used for producing electricity" and "wind is caused because of pressure differences in the atmosphere". So, what's the best answer to the question?

Select from the following.
a). Something that generates electricity
b). an automobile engine
c). The bending of a ray of light
d). Something caused by pressure differences
e). that material's properties
f). energy of moving objects
g). series of enzyme-mediated reactions
h). Faulting of rocks in the crust
The answer is:
d).