Balloons are sold in packets of $$5$$, $$10$$, and $$25$$. Marius buys exactly $$70$$ balloons. What is the smallest number of packets he can buy? (2017 Math Kangaroo Problem, Level 3 - 4, Question \#11) 
选项为:A:$$3$$  B:$$4$$  C:$$5$$  D:$$6$$  E:$$7$$  请回答其中一个选项.