A Supersonic Airplane Heats Up Considerably When Traveling Through the Air

Multiple Choice

A supersonic airplane heats up considerably when traveling through the air at speeds greater than the speed of sound. As a result, the airplane during supersonic flight is longer than when it is at rest on the ground. Offer an explanation for this length change from a submicroscopic perspective.

A) The engines on the supersonic plane are so powerful that they cause the plane's metal skin to stretch during accelerations.
B) Materials expand as they are heated.
C) Atmospheric air molecules hit the supersonic plane at great velocities causing the atoms of the planes metal skin to start moving faster.
D) Both A and B are correct.