You are presented with the quiz "The sun causes water to evaporate more, which can cause drying and what?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "the sun causes water to evaporate more quickly by adding heat" and "high humidity can cause mildew, while dry heat and direct sunlight can cause drying and cracking". 

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


 

       cracking    