You are presented with the quiz "What color are the coastal waters where bacteria and algae that use sunlight to make food?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "phytoplankton are bacteria and algae that use sunlight to make food" and "by contrast, coastal waters rich in phytoplankton are green". 

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


 

       Green    