Answer:
A. Alternate Interior Angle Theorem
Step-by-step explanation:
The Alternate Interior Angles theorem states, if two parallel lines are cut by a transversal, then the pairs of alternate interior angles are congruent.
The Alternate Exterior Angles theorem states that, when two parallel lines are cut by a transversal , the resulting alternate exterior angles are congruent.
The Consecutive Interior Angles theorem states that if the two lines are parallel, then the consecutive interior angles are supplementary to each other.
The Corresponding Angles theorem states that if two parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent.
You are given a pair of alternate interior angles WXZ and XZY, they are congruent by alternate interior angles theorem.