You are presented with the question "cutting down trees has a negative impact on the health of what?" and the following answer choices: 
- space
 - humankind
 - mars
 - aliens
 - salmon
 - Species
 - humans
 - plants

Now knowing that cutting down trees has a negative impact on an ecosystem and when ecosystems are healthy, humankind is healthy, choose the best answer.


 

  humankind       