You are presented with the quiz "What can have a negative effect on humans?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "eating food that contains pesticides can have a negative impact on humans" and "foods such as porous strawberries are hard to wash free of pesticides". 

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


 

     Eating unwashed strawberries.      