John, George and Oscar ran around the circular track in the same direction at the same time. John took 16 seconds, George took $$20$$ seconds, and Oscar took $$30$$ seconds. If they continue to chase each other, when will they meet again at the starting point? 
选项为:A:$$6$$ hours  B:$$1$$ day  C:$$4$$ minutes  D:$$124$$ minutes  E:$$9$$ hours  请回答其中一个选项.