You are presented with the quiz "what can change the color of an environment from green to brown?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "adrought can change the color of an environment from green to brown" and "drought, or a lack of water, is often a problem for farmers and communities around the world". 

So, what's the best answer to the question?


 

 lack of water          