After adding a two-digit number $$N$$ and a two-digit number that has the same digits as $$N$$ but written in reverse order, we got a square of a natural number as result. How many such numbers $$N$$ are there? 
选项为:A:$$8$$  B:$$6$$  C:$$4$$  D:$$2$$  E:other answer  请回答其中一个选项.