You need to find the set of points that will yield a slope that is the negative reciprocal of the slope of Line L because perpendicular lines have negative reciprocal slopes. The negative reciprocal of 13/7 is -7/13. Which set of points will produce this result? The formula for finding the slope is:
m = (y2 - y1)/(x2 - x1)
Consider the second set of coordinates.
(2 - (-5))/(-7 - 6) = (2 + 5)/(-13) = -7/13
The second set of coordinates satisfy the condition.