Which of the following is being constructed in the image?

Answer:
C) A line perpendicular to a given line through a point not on a line.
Step-by-step explanation:
In the given construction we draw a perpendicular line from a point which is not on line.
Please see the attachment for construction and naming of point.
Thus, C is correct option. " a line perpendicular to a given line through a point not on a line".