You are presented with the question "What does not spoil the environment?" and the following answer choices: 
- Operating a factory
 - Driving a car
 - Riding a bike
 - food and shelter
 - hydrate their cells
 - lowered energy cost
 - Burning a fire
 - peachleaf willow

Now knowing that riding a bike does not cause pollution and pollution is anything that spoils the environment, choose the best answer.


 

   Riding a bike      