Answer:
I option is right.
Explanation:
Given a line M and a point P lying outside the line (Here above)
We have to draw a perpendicular line from P to this line. i.e. we have to draw a line PQ such that PQ is perpendicular to line M, and Q is the point of intersection of perpendicular line with line M.
Just adding a point below line need not be perpendicular to the given line. Since line M contains infinite points any point connected with P need not be perpendicular to M. Hence option 2 is not correct.
We use straight edge or set square and move one leg of straight edge exactly along the line M till the point P is reached above. Now draw the line from P along set square another edge. This line would be perpendicular to M.