Y'all, a girl out. ಥ_ಥ this problem is driving me nuts, but it's simple but i can't get the answer and that's why i'm going nuts. . (╥﹏╥)

What is the question

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.