You are presented with the question "what has a negative impact on the environment?" and the following answer choices: 
- deforestation
 - deserts
 - cigarettes
 - desertification
 - humans disturb it
 - environments
 - weather
 - harmful substances

Now knowing that erosion of soil has a negative impact on the environment and desertification implies soil erosion, choose the best answer.


 

    desertification     