You are presented with the quiz "What factor is instrumental behind the change of leaf colors during the year?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "the Earth revolving around the Sun causes the seasons to change on its axis" and "gold, scarlet, and auburn leaves make a mosaic of rich colors heralding seasonal change". 

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


 

   Earth orbiting the Sun        