Answer:
B., Converse of the alternate interior angles theorem
Explanation:
We are given that
We have to find the lines must be parallel based on given information.
To find the parallel lines we will use the converse of alternate interior angles theorem.
The Converse of alternate interior angles theorem: When alternate interior angles are equal then the lines are parallel.
Reason: Given
Angle 3 and angle 13 are alternate interior angles
Therefore, by using the converse of alternate interior angles theorem
Line a and b are parallel.
option B is true.
