Hank and His Son Adam Like to Play a Game

Hank and his son Adam like to play a game on Hank's cell phone. The game involves looking at cubes with letters in them and finding words. Sometimes Hank plays below his own skill level so that Adam can win, and other times Hank plays a little harder to encourage Adam to develop his own skills. In this scenario, Hank is occupying the role of

A) mediator.
B) playmate.
C) coach.
D) social director.