Every week, Robyn swims while Sam sings.  For every $$2$$ of Sam\textquotesingle s songs, Robyn swims $$9$$ lengths.  If Robyn swims $$54$$ lengths, how many songs does Sam sing? 
选项为:A:$$6$$  B:$$8$$  C:$$10$$  D:$$12$$  E:$$18$$  请回答其中一个选项.