You are presented with the quiz "what causes rocks to crack from ice expanding into openings?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "ice wedging is when ice causes rocks to crack by expanding in openings" and "ice wedging is extremely effective in a moist but cold climate". 

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


 

      moist, cold climates     