Let's look at the given picture. Recall that vertical angles, two nonadjacent angles formed by two intersecting lines, are congruent.
As we can see, 1 and 3 are vertical angles. Therefore, ∠1 and ∠3 are congruent. Next, let's recall the definition of the Alternate Interior Angles Theorem.
Alternate Interior Angles Theorem
If two parallel lines are cut by a transversal, then each pair of alternate interior angles is congruent.
Looking at our lines, we can see that 4 and 7 create a pair of alternate interior angles.
If two parallel lines are cut by a transversal, then each pair of alternate exterior angles is congruent.
As we can see, 2 and 5 create a pair of alternate exterior angles.
This means that ∠2 and ∠5 are congruent. Option D will be true only if the parallel lines are cut by a line that is perpendicular to them. Since we do not have such information, this answer might not be true. Therefore, answer D is correct.
