Answer
d
Work Step by Step
We see that the energy used is much greater than the energy used by the lightbulb in the refrigerator. Thus, a is incorrect. Since electrical energy is required to cool the contents, even if there is a large amount of insulation, b is also incorrect. Since this energy cannot be easily used as electrical energy after use in the fridge, it is not "high quality." This leaves d as the correct answer.
