Since $$300$$ students belong to $$2$$ clubs each, there are $$600$$ club memberships. The average membership of the $$5$$ clubs is $$600\div 5 = 120$$ students. 
Each of $$300$$ students belongs to exactly $$2$$ of the $$5$$ school clubs. What is the average number of students in each club? 
[A] $$50$$ 
[B] $$60$$ 
[C] $$120$$ 
[D] $$150$$ 