Heat transfer. What happened at point C to end with D?

A) B Transferred thermal energy to A To utilize both in D. Cold always moves toward warmer areas

B)A Transfer thermal energy to B To utilize both in D. Warmer always Moves towards colder areas.

C) The surrounding air transferred thermal energy to A and B To utilize both in D. Air is the best conductor of heat.

D) This can only be possible in a controlled setting in lab