Marcello is constructing the perpendicular bisector of ab. he has already constructed arcs as shown. what should marcello do for his next step? a) place the point of the compass on point x and draw an arc using ay as the width for the opening of the compass b) place the point of the compass on point x and draw an arc using ax as the width for the opening of the compass c)use the straightedge to draw ax and ay d) use the straightedge to draw a line through points x and y