A student examines a household refrigerator. The metal coils on the back of the unit feel warm to the touch while the air inside the food compartment is cold. Student A chooses the air inside the food compartment as the system, whereas Student B chooses the external metal coils as the system. Which comparison of their descriptions of energy transfer is most consistent with thermodynamic conventions for heating and cooling?
a) Student A correctly describes the air as heating, and Student B correctly describes the coils as heating.
b) Student A correctly describes the air as cooling, and Student B correctly describes the coils as cooling.
c) Student A correctly describes the air as cooling, and Student B correctly describes the coils as heating.
d) Both students should describe their systems as heating because the refrigerator operates continuously.