Question: Robert is thinking about buying a new refrigerator. His old refrigerator runs at about 43% efficiency. Which most likely accounts for the remaining 57% of the energy?

  Options: 
 A. It is used up by the light in the refrigerator.
 B. It is released to the surroundings as heat.
 C. It is converted into mechanical energy.
 D. It stored as a form of potential energy. 
Answer: B