Final answer:
The student's behavior of sticking his tongue on the pole involved positive punishment, which decreased the behavior by adding an unpleasant stimulus.
Step-by-step explanation:
The student's behavior of sticking his tongue on the pole involved positive punishment because an undesirable stimulus (the pain of sticking his tongue) was added to decrease the behavior.
Positive punishment is used to decrease a behavior by adding an unpleasant stimulus. In this case, the pain experienced from sticking his tongue on the cold pole served as the punishment, causing the friend to never repeat the behavior.