hr1212
One way that I know is that any 2 of the 4 vertices of parallelogram needs to have either their x coordinate or y coordinate same. So in short you just need to find the missing combination of (x,y) which is (6,4) using which any 2 vertices will either have their x or y coordinates same. Is it A?
Missed the multiple selection, so (6,12) could also be another point. One way to check for all options is
to go through each options individually and validate below conditions -
1) 3 of these points don’t lie on a single line, if so eliminate
2) the point selected needs to have atleast same x or y with one given coordinate
3) distance b/w selected vertice and one given vertice is same as the distance b/w rest 2 vertices
Or if you can see the pattern in the given vertices then it’s pretty straightforward, given points (12,4) and (12,8) lie on the same line with distance of 4 b/w them so any point which is on the same line as (6,8) and has a distance of 4 will be the answer which is (6,4) or (6,12)