Which illustrates the construction of a perpendicular to a line from a point on the line?

I believe the correct answer from the choices listed above is the last option. The last option clearly describes the illustration of the construction of a perpendicular to a line from a point on the line where you start on a point in the line. Using an arbitrary radius, draw arcs intersecting the line  at two points. 
Hope this answers the question. Have a nice day.

What's the denominator