please explain

In a pie fight, each person holds a pie and throws it into their nearest neighbor. Select all people who survive (avoid getting hit) in a pie fight when people are standing in this arrangement (assuming each grid cell is 1x1, and distances are for straight lines between centers of cells). Hint: you should not need it, but just in case: a distance between points with coordinates (21, y) and (L2, Y2) is (x2 21)2 + (y2 - y)2 A C B E D OB D E