Answer:
D) same side interior angles are supplementary
Explanation:
In the attachment, yellow is what we're given and need to prove.
Green are the 2 angles that are congruent.
Blue are the 2 angles that we are given that are supplementary, with the reason that 2 angles forming a linear pair sum to 180 degrees.
Red are the 2 angles that are supplementary also, but have to find the reaosn.
We can use process of elimination as one way.
Option A is incorrect because we can see that the red angles aren't vertical.
Option B and C are incorrect because the statement isn't asking for congruency, it's asking for supplementary angles.
Option D is correct because it has to do with supplementary angles.
Also, these 2 angles are supplementary because they are same side interior angles with a transversal cutting through the 2 parallel lines.
Thus, option D is correct.
Hope this helps! :)