You are presented with the question "Air pollution can cause a decrease in what?" and the following answer choices: 
- The atmosphere
 - kinetic energy
 - smoke
 - crop yields
 - nutrients
 - Temperature
 - fires
 - smog

Now knowing that air pollution can cause the pH of soil to decrease and research has shown that soil pH less than 6.0 can decrease crop yields, choose the best answer.


 

    crop yields     