Nathan went to a photographer to have his picture taken professionally. he was given a choice of three different background colors for the picture and a choice of three different poses.
how many different picture options did nathan have?

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.