The five symbols $$\bigcirc$$, $$\triangle$$, $$\diamond$$, $$\star$$ and $$\oplus$$ used in the equations below represent different digits.  $$\bigcirc + \bigcirc + \bigcirc = \triangle$$  $$\diamond + \diamond + \diamond = \oplus$$  $$\triangle + \oplus = \star$$  What is the value of $$\star$$? 
选项为:A:$$0$$  B:$$2$$  C:$$3$$  D:$$6$$  E:$$9$$  请回答其中一个选项.