Answer:
C I think
Step-by-step explanation:
What C is essentially saying is that if the lines l and m intersect and form two angles next to each other that are equal then they will be 90 degrees
this is true because if two lines intersect they will form 4 angles and since vertical angles are equal the only way for adjacent angles to be equal is for everything to be 90 degrees which then makes the lines perpendicular
