Answer: The answer is (C).
Step-by-step explanation: Given that Celeste is constructing the perpendicular bisector of line segment ST.
Following are the steps used to draw a perpendicular bisector.
(i) First, we place the compass at the point 'S'.
(ii) Then, adjusting the compass to more than half the distance of line ST, two arcs are drawn, one above and other below the line.
(iii) We repeat the above steps for point 'T'.
(iv) Joining the meeting points of arcs above and below the line gives us the required perpendicular bisector.
Please see the attached figure, in which AB is the perpendicular bisector of ST, drawn with the help of compass and 'O' is the mid-point of ST.
Thus, the correct option is (C) Place the compass point on point S and open the compass so that the pencil point is on the segment, but closer to point T than to point S. Draw an arc on each side of the segment.