To defeat a dragon, Matthias has to cut off all the dragon\textquotesingle s heads. If he can cut off $$3$$ of the dragon\textquotesingle s heads, one new head immediately grows. Matthias defeats the dragon by cutting off $$17$$ heads in total. How many heads did the dragon have at the beginning? 
选项为:A:$$8$$  B:$$9$$  C:$$10$$  D:$$11$$  E:$$12$$  请回答其中一个选项.