To draw the perpendicular bisector of any line segment, the compass opening should be the kept constant at any value a little more than half the length of the line segment. Then the compass point should be kept on one end and arcs drawn above and below and then keeping the same compass opening the same as mentioned before, the compass point should be placed on the other end and the arcs should be drawn above and below the segment touching the previous arcs.
Thus, out of the given options, the first option best suits the next step Herberto should take.