Bud has six number cards: $\boxed{1}, \boxed{2}, \boxed{3}, \boxed{7}, \boxed{8}, \boxed{9}$.  How many cards can she choose at most to ensure that no two of chosen cards sum to $10$? 
选项为:A:$$1$$  B:$$2$$  C:$$3$$  D:$$4$$  请回答其中一个选项.