I do not really like this question in a way that you specifically pointed out in a previous video that “Coordinate Geometry” planes are drawn to scale. This means that this x-y plane is drawn to scale and one could technically draw the 45 degree line and decide wether A > B or not. Yet, the correct answer here is D. I see that, in practice", D makes sense but I guess it conveys the wrong idea that coordinate geometry drawings are not drawn to scale.
The question is valid and aligns with GRE guidelines. When we say coordinate geometry is drawn to scale, it means that if the axis scales or coordinates are provided and for eg- you visually observe a gap of 1 unit and other points are given lets say (5,3) and you see there are 4 dashes before it but nothing is marked you can assume that the points have distance of 1 between them, you can infer the other coordinates. I mean this is a very simple example but you get the point right. The property that you stated applies only to lines at a 45-degree angle, specifically the line x=y. It is not valid to assume that the line x=y passes through (x,y) without additional information, as there could be an angle difference, not necessarily 15 degrees, between the 30-degree line and the point. Therefore, your assumptions do not conform to standard GRE coordinate geometry principles. We are not given other coordinates to determine the slope, so assuming that a 45-degree line passes through this point is unfounded. I hope this clarifies your question.