John bought some cupcakes, and each of them cost $4$ dollars. He gave the salesperson $20$ dollars and got $4$ dollars as change. How many cupcakes did John buy? (Adapted from 2005 Math Kangaroo Problem, Level 3-4, Question \#3) 
选项为:A:$$6$$  B:$$8$$  C:$$10$$  D:$$5$$  E:$$4$$  请回答其中一个选项.