You are presented with the quiz "What usually changes in the autumn season?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "the color of leaves on deciduous trees usually changes in the autumn season" and "deciduous trees are Oak, Elm, Ash, Maple, and Birch". 

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


 

    the color of leaves on oaks       