There are $$17$$ balls in a bag. Each ball has a number from $$1$$ to $$17$$ on it. We randomly pick a ball from the bag. What is the smallest number of balls we have to pick in order to be sure that we have at least one pair of balls with a sum equal to $$18$$? ($$2005$$ Math Kangaroo Problem, Level $$9-10$$, Question $$ \textbackslash\# $$$$15$$ 
选项为:A:$$7$$  B:$$8$$  C:$$10$$  D:$$11$$  E:$$17$$  请回答其中一个选项.