There are $$38$$ students in the class. Each student is in either math club or music club or both. Given that among students in this class, $$26$$ students are in the math club, and $$18$$ students are in the music club, there are~\uline{~~~~~~~~~~}~students in the math club only and not in the music club. 
选项为:A:$$18$$  B:$$19$$  C:$$20$$  D:$$21$$  请回答其中一个选项.