Station 6: High-Fives - The competition is over! The 3 members of "Team Y" high-five each other. The 4 members of "Team Z" high-five each other. The supporters high-five each other.
A. In how many ways can the members of "Team Y" high-five each other only once?

B. In how many ways can the members of "Team Z" high-five each other only once?

C. In how many ways can the 150 supporters high-five each other only once?