$100-15-27-36-8=14$ 
In the class, the teacher gave $4$ numbers:$15, 27, 36, 8$. Billy added another number to make the sum result of these $5$ digits to $100$. Guess what\textquotesingle s the number Billy added ? ( adapted from $$2009$$ Math kangaroo Problems, Level $$1-2$$, Question \#$$5$$) 

A. $$13$$ 
B. $$14$$ 
C. $$15$$ 
D. $$16$$ 
E. $$12$$ 