Answer:
Perpendicular line through a point off a line
Explanation:
Based on the markings in the diagram, we have;
Marking points E and F along AB extended forms two points equidistant from the point C on the line AB
Construction of the line HI by using equal arc lengths from E and F creates two points equidistant from E and F on either side of the line AB such that HI passes through C forming a perpendicular bisector from C to AB.
Therefore, a perpendicular line has been constructed from the point C off the line AB to the line AB
Hence the correct option is the construction of a perpendicular line through a point off a line.