Answer: Third option.
Explanation:
You can know the answer by remembering the definition of perpendicular lines.
By definition, perpendicular lines are those lines that intersect at a right angle (This is an angle that measures 90 degrees).
In the equations of lines, for example, you can identify if the lines are perpendicular by comparing their slopes. If the slopes are opposite reciprocals, then the lines are perpendicular (In other words, they form an angle that measures 90 degrees).
Therefore: If two lines are perpendicular, then they intersect to form right angles.