Which expression represents the distance between point (0, a) and point (a, 0) on a coordinate grid?

The distance between any 2 points (x1,y1) and (x2,y2) is


given
(0,a) and (a,0)






the disance is a√2

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.