When liquid lemonade is placed in a freezer, its temperature slowly drops. Its molecules move less and less until they can only vibrate in a rigid structure. 
 Which of the following is another way to describe this process? 
 A. 
 Heat is removed from the lemonade, causing it to become a solid. 
 B. 
 Heat is added to the lemonade, causing it to become a solid. 
 C. 
 Heat is added to the lemonade, causing it to become a gas. 
 D. 
 Heat is removed from the lemonade, causing it to remain a liquid.