You are presented with the question "A force that keeps species what increases the productivity and stability of ecosystems?" and the following answer choices: 
- evolving
 - protect them
 - recycling
 - ligt
 - animals
 - ferns
 - trees
 - heat

Now knowing that biodiversity increases the productivity and stability of ecosystems and biodiversity is an incredibly powerful force that keeps species evolving, choose the best answer.


 

 evolving        