Hasan writes down a two-digit number. He then writes the same two-digit number next to his original number to form a four-digit number. What is the ratio of his four-digit number to his two-digit number? 
选项为:A:$$2:1$$  B:$$100:1$$  C:$$101:1$$  D:$$1001:1$$  E:It depends on his number  请回答其中一个选项.