The slope of perpendicular graphs is always the opposite reprocical to each other. This basically means the if graph a is perpendicular to graph b and graph a has a slope of 2 graph b would have a slope of -1/2 so you flip 2/1 and also change the sign. The slope of the graph we have can be found through y2-y1/x2-x1 this would give you 5-(-4)/3-(-2) and then you get 9/5 that means the perpendicular slope would be -5/9x which we see is B