The hundreds digit of a three-digit number is $2$ more than the units digit. The digits of the three-digit number are reversed, and the result is subtracted from the original three-digit number. What is the units digit of the result? (2010 AMC 8 Problem, Question \#22) 
选项为:A:$$0$$  B:$$2$$  C:$$4$$  D:$$6$$  E:$$8$$  请回答其中一个选项.