During Easter, tickets are $$$6$$ for a single person and $$$18$$ for a family ($$2$$ adults and $$2$$ children). What is the difference in price between $$4$$ single tickets and a family ticket? 
选项为:A:$$$13$$  B:$$$3$$  C:$$$4$$  D:$$$6$$  E:$$$12$$  请回答其中一个选项.