Joann has a robot toy that can walk. The robot can only walk in straight line, and each step can only walk forward for $$1$$ cm or $$3$$ cm. If the robot walks $$4$$ steps forward, it can travel~\uline{~~~~~~~~~~}~different distances. 
选项为:A:$$2$$  B:$$4$$  C:$$5$$  D:$$6$$  E:$$12$$  请回答其中一个选项.