Kaitlyn notices that her new widescreen tv's height to width ratio is 16: 9. what is this describing?

That is describing the fact that width of the rectangular screen has a relation to the height of the rectangular screen which equals to

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.