You are presented with the question "what is used for heating buildings?" and the following answer choices: 
- electrons in motion
 - protons in motion
 - coiled neutrons
 - one celled organisms
 - Movement of an air mass
 - clouds
 - igniting fuel and oxidiser
 - compound of hydrogen oxygen

Now knowing that electricity sometimes is used for heating buildings and electricity is electrons in motion, choose the best answer.


 

 electrons in motion        