(US $$1998$$ Math kangaroo Problems, Level $$5-6$$, Question \#$$15$$)When from any three-digit number we subtract that number written backwards, the difference will always be a number that is divisible by:． 
选项为:A:$$7$$  B:$$2$$  C:$$5$$  D:$$9$$  E:$$13$$  请回答其中一个选项.